[HN Gopher] Why 12 notes in Western music?
       ___________________________________________________________________
        
       Why 12 notes in Western music?
        
       Author : xchip
       Score  : 154 points
       Date   : 2022-08-29 14:51 UTC (8 hours ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | mikewarot wrote:
       | It's the same reason 12 was used as a number base so often, it
       | divides an doubling of frequency (misnamed an octave) evenly into
       | 1,2,3,4,6 and 12 parts (on a logarithmic scale), which then have
       | pleasant overtones.
        
       | dhosek wrote:
       | Some comments on tones. Pythagorean tuning is based on repeated
       | 3/2 increases in frequency with occasional halving to stay in the
       | octave, so we have, e.g.,
       | 
       | A = 1
       | 
       | E = 3/2
       | 
       | B = 9/8 (here we halved to get back into our 1-2 range)
       | 
       | F# = 27/16
       | 
       | C# = 81/64 (another halving)
       | 
       | etc.
       | 
       | Another approach is to use harmonic overtones. When a string (or
       | a column of air) vibrates, it vibrates not just at its
       | fundamental, but in a series of integer divisions of the string.1
       | 
       | Fundamental: A
       | 
       | Octave (1/2): A' (up an octave)
       | 
       | Twelfth ( 1/3 ): E (up a fifth from the octave)
       | 
       | Double Octave (1/4): A''
       | 
       |  1/5 : C#2
       | 
       |  1/6 : E
       | 
       |  1/7: G (but a bit flat from most tunings).
       | 
       | We invert wavelength to get frequencies and halve to get into the
       | 1-2 range and our E matches up at 3/2 and C# comes out as 5/4
       | which is pretty close to the 81/64 of Pythagorean
       | 
       | I would also note that 24-tone music does occur with some
       | moderate frequency in avant-garde music where half-flats and
       | half-sharps have their own notation, although these notes are not
       | easily accessible from many standard instruments, but the sound
       | of a quarter-tone difference in pitch is definitely distinct.
       | Many non-Western musics apply various micro-tonalities, such as
       | Indonesian scales which are closest to a subset of a 9-tone equal
       | temperament.
       | 
       | [?]
       | 
       | 1. In some cases, e.g., overtones of a cylindrical pipe vs
       | conical pipe, or open at both ends vs open at one end, you won't
       | get all of these tones, so a flute, which is cylindrical and open
       | at both ends can hit the fundamental and the octave, while a
       | clarinet, which is cylindrical but closed at one ends hits the
       | fundamental and then the third partial (the twelfth) but not the
       | octave.
       | 
       | 2. The place where you hear notes produced to these pitches most
       | commonly is in bugle calls: Taps, for example, would be  1/3
       | 1/3  1/4,  1/3  1/4  1/5 , etc.
        
         | ajross wrote:
         | I've never liked explaining the scale as a Pythagorean
         | derivation. It's not really correct historically (Greek music
         | didn't have anything approximating a full major scale) or
         | mathematically (it doesn't understand the idea of a "third"
         | interval the way tonal music does, so playing triads with
         | pythagorean tuning sounds awful!).
         | 
         | Here's my take: late medieval singers discovered _The Major
         | Chord_. That 's the combination of three (!) notes that is
         | "most consonant" (mathematically: beats in the shortest
         | period). This combines two notes a major fifth apart (ratio
         | 3:2), with a third note that is 5:4 with the low note. You can
         | write some code to prove this if you like.
         | 
         | So now take that "best" chord with its three notes, and start
         | moving it around. If you go up a fifth (i.e. by "the most
         | consonent interval", that is the "closest best chord to your
         | first best chord") you can play the same chord, adding two
         | needed notes that weren't in the scale before. You can likewise
         | go down a fifth to add two new notes.
         | 
         | Then you compress these seven notes into a single octave, and
         | you get... the major scale! It's just there. All you need is
         | that one "best" three-note chord and an obvious metric for
         | "nearest" (i.e. transpose by a fifth) and you have almost all
         | of modern tonal music. Play the same tunes starting on
         | different notes and you get "modalities", etc... You can
         | transpose up and down to nearby keys and keep playing by
         | "cheating" with your tunings to move a note half way up or
         | down.
         | 
         | And the practice of formalizing those transpositional cheats
         | because what we now know as the equitempered scale. But they're
         | still just cheats. And the fact that pow(2, 1.0/12) happens to
         | work is, basically, just dumb luck.
        
       | jbverschoor wrote:
       | 12 notes, 12 hours, 12 months., even 12 monkeys.
        
         | lioeters wrote:
         | > The duodecimal system, which is the use of 12 as a division
         | factor for many ancient and medieval weights and measures,
         | including hours, probably originates from Mesopotamia.
         | 
         | https://en.wikipedia.org/wiki/Duodecimal#Advocacy_and_%22doz...
        
           | retrac wrote:
           | Yep. 60 seconds, 60 minutes, 12 hours. To the Sumerian mind
           | that was apparently as nice and round as 100 seconds, 100
           | minutes, 20 hours.
           | 
           | 60 is the smallest composite number with three prime factors,
           | and divides evenly by 2, 3, 4, 5, 6, 10, 12, 15, 20, 30.
           | Decimal only divides by 2 and 5. Makes arithmetic by hand a
           | lot easier. Duodecimal has a similar advantage.
        
             | mandmandam wrote:
             | > 60 is the smallest composite number with three prime
             | factors
             | 
             | Er, that'd be 30 I think, but the main point stands.
        
               | BitwiseFool wrote:
               | 2 is such a nifty prime, we multiplied by it twice. It
               | was just too perfect not to.
        
       | 752963e64 wrote:
        
       | kazinator wrote:
       | When we divide the octave into various equal steps using equal
       | temperament, we find that there is a local maximum at 12, which
       | yields a good approximations for important intervals.
       | 
       | But the "why" cannot be explained just using arithmetic. There is
       | a history behind it. Twelve note instruments didn't begin with
       | equal temperament.
       | 
       | There are twelve notes in western music because the diatonic
       | scale has 7 notes, and alterations of these notes add five more,
       | if you aren't picky about microtonal differences.
       | 
       | If you have do-re-mi-fa-so-la-ti-do, there is a small step
       | between "mi-fa" and "ti-do" which is _about_ half of the longer
       | step that is observed in the five remaining successive pairs. If
       | you identify some half-step note between those other pairs like
       | "do-re" or "so-la", you end up with five more notes, giving you
       | twelve. That's all it is; if we back fill 7 notes with enough
       | notes to have chromatic half steps, we get 12.
       | 
       | Now, early practitioners of western music did know that that's
       | not all there is to it: that a G# is not the same as an Ab. They
       | tried using the in-between notes for transposing to other keys
       | and found that the keys sounded different. They knew all about
       | the mathematics behind it and the Pythagorean comma: that if you
       | go around the circle of fifths 13 times, you don't end up at
       | exactly the same note (modulo octave); there is a discrepancy.
       | 
       | Various technical devices were devised, such as splitting the
       | small keys of keyboard instruments, so that the G# key actually
       | had a G# split and an Ab split. Various tunings were also used,
       | like well temperament. Bach's Well-Tempered Clavier is basically
       | a set of test cases for tuning.
       | 
       | We settled on equal temperament because it distributes the error
       | such that all the keys sound the same; when music is transposed
       | to any key, the pitch relationships are preserved.
       | 
       | Going back to the first concept; why wouldn't more than five
       | additional tones be added to add color to a seven tone scale?
       | It's because Western music traditionally hadn't been oriented
       | toward recognizing microtonal differences, or at least into
       | organizing them (where they exist) into a single system.
       | 
       | In Indian music, there are 22 notes (shrutis). They are needed
       | because there are numerous scales which have the same
       | approximation on a western instrument. For instance, there are
       | multiple scales that resemble "do-re-mi-fa-so-la-ti-do": the
       | Pythagorean scale, but which use different microtones chosen from
       | the 22 shrutis. Those scales all have different names; they are
       | not just different tunings for obtaining different flavors of do-
       | re-mi.
       | 
       | But in Indian music, there is still a significance in 12 tones in
       | an octave!
       | 
       |  _" There are 12 universally identifiable notes ('Swaraprakar' in
       | Sanskrit) in any Octave (Saptak). As we play them from one end on
       | any string, the perception of each of these 12 changes 'only' at
       | 22 points given by nature (See numbers in green in the slide
       | below). The sounds produced at these 22 points are the '22
       | Shrutis' and the 3 types of distances in-between are called as
       | 'Shrutyantara' (in Sanskrit) (See Legend below)"_
       | http://www.22shruti.com/
       | 
       | And:
       | https://en.wikipedia.org/wiki/Shruti_(music)#Identification_...
       | 
       | It seems there is no getting away from the situation of there
       | being identifiable 7 note scales (Swaras), into which we can
       | stuff five more notes to obtain some kind of twelve-note
       | chromatic scale.
        
         | aidenn0 wrote:
         | You also get the western[1] chromatic scale if you go up by a
         | fifth (which is pleasant sounding for many reasons) ad
         | infinitum.
         | 
         | C -> G -> D -> A -> E -> B -> F# -> C# -> G# -> D# -> A# -> E#
         | -> B#(C)
         | 
         | Of course the B# you end up with at the end is 531441/4096
         | which is 1.3% higher frequency than 7 octaves above the
         | starting C. If you want to generate flats as well, by traveling
         | in the opposite direction, you end up with different notes for
         | the flats. 12-TET is just the modern way of using a constant
         | frequency ratio to divide the octave to match the 12 notes used
         | by Pythagoras. The ancient greeks were unlikely to come up with
         | it due to the reliance on irrational numbers.
         | 
         | 1: Pythagoras is often credited with this scale, China also
         | independently invented this scale and it's not clear which came
         | first (https://en.wikipedia.org/wiki/Sh%C3%AD-%C3%A8r-l%C7%9C)
        
           | kazinator wrote:
           | That's just from modulo math. A fifth is 7 semitones, which
           | is relatively prime to 12. Thus 7x (mod 12) hits all the
           | elements of the modulo 12 congruence for x in 0..11. We cover
           | all notes in the first twelve steps.
           | 
           | But say we are not assuming a twelve note system in the first
           | place; how do we get twelve notes?
           | 
           | Going up a fifth and then down a fourth is very close to a
           | tone. We can do that five times before we approximately hit
           | an octave, yielding six notes. The fifths above those notes
           | are six additional notes.
           | 
           | We see that in your diagram:
           | 
           | C -> G -> D -> A -> E -> B -> F# -> C# -> G# -> D# -> A# ->
           | E# -> B#(C)
           | 
           | in that we can interpret every other note as the whole tone
           | scale:
           | 
           | C -> D -> E -> F# -> G# -> A# -> B#(C)
           | 
           | and their fifths:
           | 
           | G -> A -> B -> C# -> D# -> E# -> Fx(G)
           | 
           | Fifths fill the gaps in the whole tone scale to recover the
           | other whole tone scale.
           | 
           | Going back to the 12 tone math again, 2 and 12 have a common
           | divisor, so steps of 2 modulo 12 cycle through 6 symbols.
           | There are 6 others left out, reachable by some relatively
           | prime step like 7 (perfect fifth).
        
             | aidenn0 wrote:
             | > That's just from modulo math. A fifth is 7 semitones,
             | which is relatively prime to 12. Thus 7x (mod 12) hits all
             | the elements of the modulo 12 congruence for x in 0..11. We
             | cover all notes in the first twelve steps.
             | 
             | > But say we are not assuming a twelve note system in the
             | first place; how do we get twelve notes?
             | 
             | My diagram showed an (approximate) 12 note cycle assuming
             | only a 3:2 ratio for a fifth. There are lots of good
             | reasons to use a fifth as the basic interval[1]. In no way
             | does this assume a 12-note system.
             | 
             | The 12 notes don't come from "filling in" between the 7
             | notes of the diatonic major scale, they come from
             | continuing the pattern until a near-cycle happens; is your
             | argument that the 1.2% error in the cycle is arbitrary?
             | it's less than 1/4 the next largest difference and slightly
             | more than the rule of thumb for how much "anybody" can
             | hear. The next time we get closer to a cycle is at 41, and
             | we don't get closer by an order of magnitude until 53.
             | 
             | 1: And in fact the fifth is used as a basis for many other
             | scales both western and otherwise (Note that the first 5
             | notes are the major Pentatonic scale and the first 7 are
             | the major diatonic scale).
        
       | plq wrote:
       | The system of the Turkish Classical Music is a bit different:
       | 
       | * https://www.sufi.gen.tr/nota-sistemi/en
       | 
       | * http://www.turkishmusicportal.org/en/types-of-turkish-music
        
       | j7ake wrote:
       | With digital pianos, I imagine it is easy to switch to different
       | tunings so that you can play each piece in a tuning that fits the
       | key? Would be a major advantage over acoustic pianos.
        
         | dhosek wrote:
         | There are keyboards that will do this. I remember seeing this
         | advertised back in the 90s.
        
       | abetusk wrote:
       | This comes up every so often and in my mind, there is an answer
       | and it has to do with how well the notes in the "temperament"
       | combine to produce near-enough approximations to simple
       | fractions.
       | 
       | That is, take a temperament, combine each pairs of notes
       | together. For each pairs of notes, find a close-enough fraction
       | to it and give it a score depending on how many of these pairs
       | produce simple fractions.
       | 
       | The 12 note equal temperament produces one of the best scores,
       | assuming some (perhaps arbitrary) constraints.
       | 
       | There are some papers getting at this idea [0].
       | 
       | I even wrote a small program to try and do this [1]. Farey
       | sequences are used for best rational approximation [2] [3].
       | 
       | I think this even gets at why some chords sound "sour/sad" while
       | others sound "happy/full", because they have less or more
       | constructive interference between the notes in the range of where
       | we can hear.
       | 
       | Obviously this has a lot to do with culture, so it's not as clear
       | cut but at least this approach is better than just thinking it's
       | completely arbitrary.
       | 
       | [0]
       | https://www.researchgate.net/publication/267806865_Measures_...
       | 
       | [1]
       | https://github.com/abetusk/scratch/blob/release/src/music/be...
       | 
       | [2] https://www.johndcook.com/blog/2010/10/20/best-rational-
       | appr...
       | 
       | [3] https://en.wikipedia.org/wiki/Farey_sequence
        
       | buildsjets wrote:
       | "Flying Microtonal Banana" - because why not fret a whole bunch
       | of guitars for 24-Tet and record an album?
       | 
       | https://guitar.com/news/music-news/king-gizzard-stu-mackenzi...
        
       | mcbrit wrote:
       | Let's talk about splitting things up in useful ways.
       | 
       | 12=2 * 2 * 3.
       | 
       | Splitting something in half is useful; splitting it half again
       | remains useful. Splitting in half a third time is arguably less
       | useful than splitting it into a third. So 12 is the made-to-order
       | number that lets you split it in half, twice, and in thirds,
       | once.
       | 
       | Which naturally leads to seconds and minutes, or 60:
       | 
       | 60=2 * 2 * 3 * 5
       | 
       | Because dividing the whole into fifths is more useful than a
       | second 3, or a third 2.
       | 
       | So, there's your basic argument for why you would see a 12 or a
       | 60 instead of a 10 or some other number. You have a whole that
       | you want to divide into useful parts.
       | 
       | I'm not sure that the linked article, or the current top comment
       | (Circle of Fifths) meaningfully extends beyond this "useful
       | parts" hypothesis; we like hearing useful parts would be the
       | somewhat surprising thing to talk about.
        
         | nikeee wrote:
         | These numbers are called "Highly Composite Numbers" [0].
         | Basically, it is a series of numbers where each number has more
         | factors than the number before it (and is the first number with
         | that number of factors). As you hinted, they are especially
         | useful if your number system does not have fractions or decimal
         | places and you still want to divide things.
         | 
         | You may recognize the beginning of the series: 1 2 4 6 12 24 36
         | 48 60 120 180 240 360 720
         | 
         | Numberphile [1] calls them "Anti-Primes".
         | 
         | [0]: https://en.wikipedia.org/wiki/Highly_composite_number [1]:
         | https://www.youtube.com/watch?v=2JM2oImb9Qg
        
       | coldtea wrote:
       | > _You may have noticed that 24 is also includes the 5ths and
       | 4ths, the problem is that having twice as many notes would
       | require instruments with twice as many keys or buttons making
       | them more expensive and complicated to play, also probably we
       | wouldn 't notice the difference between notes that are so close_
       | 
       | We actually would, and it's quite noticable. Several cultures use
       | microtonals intervals with half-half-steps or similar.
       | 
       | The main reason we stuck with 12, is complexity in making AND
       | playing an instrument with so many notes - that, or the halved
       | range, if we keep the number of notes on the instrument the same.
       | 
       | But there are cultures (and instruments) which have more.
        
       | sleepdreamy wrote:
       | Micro-Tonal bands such as King Gizzard play around/bend the rules
       | on the whole 12 notes in music thing.
        
         | joegahona wrote:
         | Familiar with the band, but not examples of this. Can you
         | recommend any tracks that demonstrate?
        
           | inkcapmushroom wrote:
           | Their albums Flying Microtonal Banana, KG, and LW are all
           | microtonal, so anything from those albums. Rattlesnake,
           | Billabong Valley, Intrasport, the Hungry Wolf of Fate, etc.
        
       | dr_dshiv wrote:
       | I suspect it has something to do with resonance. Resonance occurs
       | when frequencies match approximately. It isn't just in the
       | fundamental or pitch frequency of two notes-- resonance can also
       | occur via frequency matching in the shared overtones of two
       | notes.
       | 
       | Consonant notes tend to share a lot of overtones. I have heard
       | that the pentatonic scale maximizes internote resonance. This
       | seems relatively straightforward to test empirically.
       | 
       | The first known scientific experiment (empirical test of
       | mathematical model) was the attested case of the pythagoreans
       | casting bronze chimes in the same rational proportions of lengths
       | of a string. The experiment demonstrated that small integer
       | ratios produce consonance.
       | 
       | Here is the most recent and up-to-date theory of harmony in music
       | (that I know):
       | https://downloads.spj.sciencemag.org/research/2019/2369041.p...
        
       | euroderf wrote:
       | A long-winded way of saying that if you want to hit the 3:2 and
       | 4:3 sweet spots "closely enough", dividing the octave into 12
       | logarithmically equidistant bins works very well, and better than
       | any other number of bins less than 50 (or maybe 30).
        
       | locusofself wrote:
       | I'm not a music theory expert, just a guy who has played guitar
       | by ear for 28 years.
       | 
       | Equal temperament is definitely a compromise .. I find myself
       | constantly trying to "sweeten" the tuning of my guitar strings
       | relative to the song/key I am playing.
       | 
       | You can tune your guitar with the most accurate guitar tuner in
       | the world (I have strobe tuners by Sonic Research and Peterson),
       | and some things still just sound out of tune.
        
         | criddell wrote:
         | There are guitars with frets that aren't straight lines that
         | try to address some of the problems:
         | 
         | https://guitargearfinder.com/faq/true-temperament-frets/
        
           | khitchdee wrote:
           | FWIW, A sitar also has a 12 note scale, but the frets are
           | moveable so you can tune by ear. The drawback is, you only
           | play melodies on the top string and there are no chords. It's
           | possible to design a guitar where the frets are spaced at
           | harmonic intervals and not equal tempered, but then, you can
           | only play in one key, the key of E and you can't capo or play
           | barre chords. However, if you do play such a redesigned
           | guitar in the key of E, it will sound sweeter because all
           | your notes will be harmonic and you could play chords.
        
           | locusofself wrote:
           | I've seen those! Pretty cool. I've also seen people put
           | intermediate frets on certain notes.
        
           | tshaddox wrote:
           | I'm a bit confused by that article. It says things like "the
           | problem is that equal temperament isn't perfect" and "because
           | guitars are imperfect instruments, they can never be
           | completely in-tune" and "if you tune your open strings
           | perfectly to pitch, you may still notice that some chords
           | sound slightly out-of-tune."
           | 
           | That doesn't sound like a description of a problem with equal
           | temperament. In fact, the whole point of equal temperament is
           | that any given chord has precisely the same tuning in every
           | key. Isn't the purpose of these staggered frets to tune the
           | guitar to more accurately match equal temperament? In other
           | words, a guitar string played on the 7th fret is _supposed_
           | to be tuned exactly 7 12-TET semitones above that string
           | played open, but with completely straight frets (in lines
           | exactly perpendicular to the strings) it 's difficult to get
           | every fret on every string to be accurately tunes.
           | 
           | I believe this is what's referred to as intonation. Many
           | guitars have some form of manual adjustment, like a movable
           | bridge saddle for each string, and it's common to use that to
           | slightly adjust the length of each string so that e.g. the
           | 12th fret is accurately in tune with the open string. These
           | "true temperament" guitars seem to have done a similar thing
           | but with small adjustments to each fret on each string.
           | Presumably the fret arrangements are designed to match that
           | exact guitar fretboard with some specific guitar strings?
           | 
           | The article says "with a normal guitar, if you play an A
           | Major chord, then play a D Major chord, those chords will be
           | slightly out-of-tune with each other." Again, this doesn't
           | sound like a description of a problem with equal temperament.
           | From what I can tell, these "true temperament" frets would
           | help specifically with playing the same chord/interval in
           | different positions.
        
             | xhevahir wrote:
             | I mentioned this fretboard yesterday in another thread (
             | https://news.ycombinator.com/item?id=32626218 ). One of the
             | main proponents of the design talks about its advantages
             | here: https://youtu.be/D8EjCTb88oA
             | 
             | I'm not crazy about the sound, myself. It's kind of like a
             | guitar sample played through a MIDI keyboard.
        
               | tshaddox wrote:
               | Yeah, that video is linked from the article I was
               | responding to. The video certainly makes sense: he's
               | demonstrating that intervals sound the same in every
               | position and specifically that octaves are very in tune
               | across huge distances on the fretboard.
               | 
               | From the small clips I've heard, it sounds great to me,
               | especially when the guitar is playing alone. Back when I
               | played a lot of guitar I was often pretty bothered by
               | intonation issues, even with decent gear that was setup
               | well and didn't seem to bother other (much better)
               | guitarists. But of course guitars often play together
               | with 12-TET instruments that are likely to be much more
               | accurately tuned (like a piano or organ), and it makes
               | sense that the every-so-slightly out-of-tune nature of
               | guitars has become part of what sounds distinctively
               | _guitar-like_ , especially the specific tuning you're
               | likely to hear a lot with common guitar chord voicing in
               | many styles of music.
        
         | InCityDreams wrote:
         | Apart from ensuring my intonation was spot on, and my frets
         | nicely shaped, scalloping my frets allowed me a lot of what may
         | be the 'sweetness' you are after - a slightly harder pressure,
         | without finger gymnastics, allows minor pitch corrections (but
         | you can't go flatter). Regular guitars just seem dead to me. I
         | also shaved parts of my neck - significantly - along different
         | parts of it ie it's not 'smooth', it's shaped only for me, and
         | how i want to play in the different registers.
        
       | SeanLuke wrote:
       | We've seen this before: and it's likely wrong. He ended his
       | experiment too soon at 24 divisions, but even a little googling
       | should have told him to go to 31, which is more accurate than 12.
       | 
       | The 12-note scale long predates the notion of just or equal
       | temperament.
        
         | ledauphin wrote:
         | i don't think this post is making any arguments about
         | _accuracy_ - the point is that 12 is the _simplest_ (smallest)
         | number that gets reasonably close.
         | 
         | Simplicity is incredibly powerful.
        
         | elihu wrote:
         | For the intervals they look at in the article, the perfect 4th
         | and 5th, 31-EDO is worse -- about 5 cents of error, versus
         | about 2. What 31-EDO has is a major third that's almost dead-
         | on, and a minor third that's a lot closer.
         | 
         | https://en.wikipedia.org/wiki/31_equal_temperament#Interval_...
         | 
         | 41-EDO though has a perfect 4th and 5th that are closer than
         | 12-EDO, being off by about half a cent rather than about 2
         | cents. In fact, 41-EDO is better at every commonly-used
         | interval than 12-EDO, plus it adds a lot of very good 7-limit
         | intervals too (i.e. ratios with sevens in them like 7:4, which
         | is way off in 12-EDO).
         | 
         | By a weird set of mathematical coincidences, 41-EDO is actually
         | quite playable on guitar with the right layout. The trick is to
         | omit half the frets and tune the strings so that each string
         | has the notes that the strings above and below it lack. Tuning
         | by major 3rds, you get a whole lot of useful notes clustered
         | where they're easy to play. There's a handful of us (in
         | Portland mostly) trying to promote this idea:
         | https://kiteguitar.com/
        
         | [deleted]
        
         | bryanlarsen wrote:
         | According to https://news.ycombinator.com/item?id=32641527, 12
         | is substantially more accurate than 31. 41 is slightly more
         | accurate, and 53 is a lot more accurate.
        
         | lynndotpy wrote:
         | Even better, if we abandon the idea of an octave base of 2, we
         | can get other scales. What divisions lie between, say, powers
         | of 3 or 5?
         | 
         | (You can find these naively by brute force!)
        
       | thomasqbrady wrote:
       | This piece is a good example of circular reasoning, isn't it? The
       | question "Why are there 12 notes in Western scales?" Is answered
       | first by presuming that 4ths and 5ths sound pleasant (to whom? a
       | Westerner?), the "4th" and "5th" being intervals ON a Western
       | scale, which the author then reverse-engineers back to the
       | 12-note scale which they assumed from the start. There are other
       | scales you could start from, in which 4ths and 5ths aren't so
       | special...
        
         | bryanlarsen wrote:
         | The why is because the 5th is the primary non-octave overtone
         | of a vibrating string, and the 4th is an inverted 5th.
        
         | diffeomorphism wrote:
         | No, not at all.
         | 
         | > 4th and 5th being intervals ON a Western scale.
         | 
         | That is where you went wrong. They are not. They naturally
         | arise as small integer frequency multiples/fractions on any
         | string instrument (wave lengths 1, 1/2, 1/3,...). They are
         | hence quite obvious/loud (and humans recognize patterns as
         | pleasant for whatever reason). Once you have 4ths and 5ths you
         | repeat to get the Western system (handwaving away that this
         | does not actually close, but "rounds" to make it fit into
         | twelve. That is a whole other subject).
         | 
         | This is a pretty good example of inductive reasoning. We want a
         | system that for any note also includes its first few harmonics,
         | show that this implies....
        
           | thomasqbrady wrote:
           | I guess I wasn't clear. I'm not saying the 4th and 5th notes
           | don't have a special sound to anyone. I'm saying that 1) just
           | exactly how important their resonance is to you is influenced
           | by your culture. It's not that atonal musicians didn't notice
           | the resonance. They weren't drawn to it as much. 2) The logic
           | given was "if you want your scale to include the 4th and 5th,
           | then 12 notes is inevitable." The "if you want your scale to
           | include the 4th and 5th" is the a built in assumption that
           | you want something like the western scale, so it doesn't seem
           | that impressive to me that they then arrive at the 12-tone
           | scale.
        
         | herghost wrote:
         | Thank you! After reading the article I was left unsatisfied,
         | but couldn't put my finger on it. I was somewhere around
         | thinking that we hadn't yet established why 4th and 5th
         | intervals were particularly special and so I couldn't see why
         | the conclusion worked.
         | 
         | You nailed it.
        
           | pdonis wrote:
           | _> I was somewhere around thinking that we hadn 't yet
           | established why 4th and 5th intervals were particularly
           | special_
           | 
           | Other responses to the GP have explained that. The article
           | itself also mentions the reason (small integer ratios).
        
         | mcphage wrote:
         | That's not really circular, though. It does start from the
         | assumption that 4ths and 5ths sound pleasant, but uses that to
         | build possible scales, some of which are more compatible with
         | 4ths and 5ths than others.
        
         | jollybean wrote:
         | No, 4ths and 5ths are resonant. They sound better to a lot of
         | people. They are completely distinguishable from arbitrary
         | intervals right near there.
         | 
         | Most of the notes on the Western scale fall into this
         | orientation, i.e. there is reasoning for it. It's not just
         | arbitrary.
        
       | papandada wrote:
       | 3^12 is within 1.5% of 2^19
        
       | analog31 wrote:
       | An alternative question is: Why not more? There are approximately
       | rational scales with more than 12 notes. Something I wonder is
       | how the complexity of music relates to its use. For instance,
       | instruments for music that's primarily ceremonial, or used in
       | centralized locations by trained experts, could adopt scales with
       | more notes, or more difficult tunings. This includes 12TET, which
       | was difficult for an untrained musician to replicate, and
       | unlikely to stay in tune for an entire performance on some
       | instruments.
       | 
       | Simpler tunings might lend themselves to instruments that were
       | homemade, used for folk music, carried by travelers, played at
       | home, etc. In fact those two things could coexist within a single
       | culture. There were pipe organs and folk fiddles in Europe during
       | the same time period, after all. Once the 4 strings are tuned by
       | means of an easily discerned interval, you can fill in with a
       | tolerable scale by ear.
       | 
       | "Carried by travelers" suggests an advantage for a tuning system
       | that can be restored by a non-expert and used for music that
       | spreads from town to town.
        
       | MatthiasWandel wrote:
       | There was 12 notes before there was even division. It was Bach
       | that pushed equal temprament (equal spacing). Before that, the
       | ratios were actual ratios (perfect 4ths and 5ths), though you
       | couldn't just transpose music and expect to sound good.
        
         | dahart wrote:
         | > it was Bach that pushed equal temperament (equal spacing).
         | 
         | Not really. Equal temperament was being advocated both in China
         | and Europe long before Bach was born. In Europe, it was the
         | lute players that pushed for it, because it matters more for
         | fretted instruments, where any temperament other than equal
         | causes conflicts and inconsistencies on the neck.
         | 
         | https://en.m.wikipedia.org/wiki/12_equal_temperament
        
         | sabotista wrote:
         | Pythagoras is believed to have come up with the just intonation
         | (exact rational) figures. At the time, irrational numbers were
         | distrusted and despised so, as you noted, the perfect fifth
         | really was exactly 3:2.
         | 
         | But it's likely that a 12-tone system won out because lg(3/2)
         | is so close to 7/12, even if this was never a conscious
         | decision. 19, 31, and 53 are also credible candidates per
         | continued fraction expansion, but unwieldy for physical
         | instruments (although some computer music does use 53-TET).
        
           | not2b wrote:
           | Pythagoras and his followers at first thought that irrational
           | numbers didn't even exist, though the story that they drowned
           | a guy for proving by contradiction that sqrt(2) is irrational
           | is probably not right. Rather, strings with length ratios
           | made of small integers, like 2/3 or 3/4, sound good
           | (harmonize) when played together. So the started with the
           | ratios, because that's what made sense. Not to use ratios was
           | considered, well, irrational. :-)
        
             | dhosek wrote:
             | It may not be true, but I still loved telling that story to
             | my students.
        
         | thirteenfingers wrote:
         | IIRC the system Bach was pushing wasn't actually equal
         | temperament, but "well temperament" which was some sort of
         | compromise between equal temperament and having pure fifths
         | everywhere. The result was that all twelve keys sounded
         | acceptable, but some keys had purer fifths or thirds than
         | others. Some musicians/scholars say that Bach composed the
         | different preludes and fugues specifically to use the resulting
         | different characters of the different keys to the best possible
         | advantage. I can't speak to this personally, I keep my piano at
         | equal temperament ;)
         | 
         | (Big fan of your videos btw)
        
           | joegahona wrote:
           | This is my understanding too. I have a Kurzweil K2500
           | keyboard from around 1999 that has a bunch of the alternate
           | tunings, including three from that era. The Bach-era tunings
           | weren't what we know of as "equal temperament." Truly equal
           | temperament didn't come around until well after Beethoven was
           | dead. I've always interpreted the "Well-Tempered" in Bach's
           | title to mean that he was brining out the strength of each
           | key. Some of those keys sound really "out of tune" to modern
           | ears -- I have a friend with perfect pitch who legit can't
           | listen to them.
           | 
           | Owen Jorgensen's "Tuning the Historical Temperaments by Ear"
           | is good bedtime reading on this topic, if you have a couple
           | hundred bucks burning a hole in your pocket.
           | https://www.amazon.com/Tuning-historical-temperaments-ear-
           | ei...
        
             | wizofaus wrote:
             | > Truly equal temperament didn't come around until well
             | after Beethoven was dead
             | 
             | Source for that? The concept and practice certainly existed
             | well before Beethoven's time but it's less clear at which
             | point it became the norm. Even the wikipedia article on 12
             | TET has "citation needed" for the claim that it happened in
             | the early 19th century.
        
               | joegahona wrote:
               | I don't remember where I learned this, but what you said
               | is more accurate than what I said -- the concept was
               | definitely known well before Beethoven, but my
               | understanding is it wasn't the standard tuning on
               | keyboard instruments until much later, and came to its
               | fruition with all the atonal music of the early 20th
               | century. I think composers even went so far as to assign
               | emotions/moods to various keys based on each key's sound.
               | E.g. "E-flat major is austere, D-minor is sad," etc.
               | 
               | Might be worth reading:
               | 
               | - https://books.google.com/books/about/The_Effects_of_Une
               | qual_...
               | 
               | - https://www.proquest.com/openview/b22142f819768ae82464a
               | a2679...
        
               | wizofaus wrote:
               | I still feel that way about certain keys, even playing on
               | an exactly equal tempered keyboard. I don't think the
               | degree to which certain intervals might vary between keys
               | is necessarily the important factor.
        
               | joegahona wrote:
               | Those descriptors ("austere," etc.) have always struck me
               | as subjective -- I'm not one to tell people what mood
               | they're getting from certain keys. But a root major chord
               | will have a much different feel in, e.g., C#-major on an
               | 18th-century tuning than in equal temperament.
               | 
               | I have this CD [1] in a box somewhere but can't find it
               | on Youtube. It's a few Beethoven sonatas in the
               | temperament he would've used. Just sounded out-of-tune to
               | me in certain parts (especially during the Waldstein),
               | but I don't have perfect pitch. The booklet that came
               | with that CD is really helpful in understanding all this,
               | and I think that might be where I learned about that Owen
               | Jorgensen tome.
               | 
               | There's no shortage of similar experiments on Youtube.
               | This one [2] has a wild one in just intonation, but I
               | doubt that temperament was still used when Mozart was
               | composing.
               | 
               | [1] https://www.amazon.com/Beethoven-Temperaments-
               | Historical-Tun...
               | 
               | [2] https://www.youtube.com/watch?v=lzsEdK48CDY
        
               | wizofaus wrote:
               | Thanks for that link, I don't know if it demonstrates
               | "just intonation" though? But the 1/4 Comma Meantone
               | tuning just sounds horrible the moment a diminished chord
               | comes into the picture.
        
               | tripa wrote:
               | More generally, I'd be curious to know how they'd
               | practically tune a keyboard to 12TET before the
               | electronic chromatic tuner got around. Start with
               | Pythagorean fifths then compress ever-so slightly? How'd
               | you keep them... equal?
        
       | captain_trips wrote:
       | I usually think of it as someone hundreds of years ago playing
       | with a tighly stretched string and noticing stuff:
       | 
       | - Half a string's length is the same thing, just higher
       | 
       | - The harmonic at half a string is the same thing, just higher
       | 
       | - The harmonics at 3:2 and 4:3 are really loud and distinct
       | 
       | - If you chop up the rest of the string at the same interval as
       | the 3:2 and 4:3, some have strong harmonics that match tones on
       | the string, some don't
       | 
       | Then I figure with the Octave, 5th, 4th, and M3 as the strongest
       | harmonics that matches other lengths (or octaves thereof), they
       | went from there...
        
       | srcreigh wrote:
       | There was 12 notes in Western music before 12 equal divisions.
       | 
       | This Mozart piece played in mean-tone temperament (historically
       | accurate) has better tensions and resolutions than the equal
       | tempered version.
       | 
       | https://www.youtube.com/watch?v=lzsEdK48CDY&t=700s
       | 
       | (The chipper ending to this piece is believed to be not written
       | by Mozart.. the song was incomplete when he died.)
       | 
       | I even prefer Chopin in unequal temperament, but I'm not as
       | confident about whether Chopin used 12 equal divisions.
       | 
       | https://www.youtube.com/watch?v=fJT5Q6HooyA
        
       | TheOtherHobbes wrote:
       | 12 notes tuned in equal temperament is a workable compromise
       | between musical expressiveness, harmonic ratio accuracy,
       | readability, and finger precision.
       | 
       | It's also an established standard, which is a huge deal because
       | it means you have access to a huge established repertoire.
       | 
       | A 31-TET acoustic piano would be huge, extremely complicated, and
       | probably unplayable. Smaller instruments mostly just aren't
       | practical. In theory you can play with more precision on fretless
       | instruments (including strings), but it's hard enough to get
       | beginners to pitch 12-TET accurately.
       | 
       | Electronic microtonal keyboards exist, but they require extra
       | learning and the music you can make with them isn't compelling
       | enough to justify the complexity.
       | 
       | https://www.youtube.com/watch?v=9ZozXzKOf8o&t=94s
        
         | gnulinux wrote:
         | Not a musician, but as a hobbyist composer and music theory
         | enthusiast, I think anything more than 24-TET is overkill in
         | terms of daily practice. I don't think there is sufficient
         | expression to adding anything more than quartertone to justify
         | making your theory and practice so much more complicated.
         | 24-TET is convenient because all your 12-TET theory works
         | exactly the same, except now you have quartertone, in addition
         | to semitone. This gives really interesting intervals, although
         | not all of them will be usable in practice. In terms of
         | instrument practice, 19-TET is a good middle ground since it
         | maps unambiguously to 12-TET while introducing useful and
         | expressive intervals such as septimal minor third.
        
         | TakeBlaster16 wrote:
         | I think 19-TET is the most viable alternative to 12-TET. It
         | fits in a standard piano form factor by adding a few black
         | keys, and uses the same note names everyone is used to.
         | https://commons.wikimedia.org/wiki/File:19_equal_temperament...
         | 
         | And it sounds really unique!
         | https://www.youtube.com/watch?v=bJfTu1Y2H44
        
           | diydsp wrote:
           | 22-TET is a sweet spot in the curve of "Average Error
           | Distance From Harmonic Interval" http://www.gweep.net/%7Eshif
           | ty/portfolio/musicratios/index.h...
        
         | shams93 wrote:
         | Thats a decent explanation but in other cultures like Turkish
         | music you have 9 other notes in the space of one half step so
         | losing those extra notes will make the music sound like faked
         | Turkish music without those extra pieces.
        
         | dmarchand90 wrote:
         | There used to be a lot of tempers floating around. For example
         | a lot bach's music is not really supposed to be played in
         | modern equal temper https://www.ethanhein.com/wp/2020/what-
         | does-the-well-tempere....
        
           | analog31 wrote:
           | I consider the 12 tone scale to be a technology. The
           | historical temperaments were compromise solutions to the
           | problem of getting a useable scale within the skills and
           | patience of the musician. A harpsichord had to be tuned
           | before every performance, by the musician.
        
           | WalterSear wrote:
           | It's still twelve notes.
        
         | elihu wrote:
         | 41-EDO is surprisingly playable on guitar, if you omit half the
         | frets. The trick is to tune the strings so that each string
         | only has half the notes, but the notes that aren't there are
         | available on neighboring strings. It seems like it shouldn't
         | work, but it does.
         | 
         | https://kiteguitar.com/
         | 
         | https://kiteguitar.com/theory/fretboard-charts-downmajor-tun...
        
       | acadapter wrote:
       | The 12 tone scale provides good approximations of many
       | aesthetically pleasing (mathematically simple) intervals.
        
       | waffletower wrote:
       | Bach explored another consideration, key changes within
       | compositions, quite thoroughly: for example:
       | https://en.wikipedia.org/wiki/The_Well-Tempered_Clavier. You can
       | also consider the group theoretic explanation as well (sorry
       | paywall): https://www.jstor.org/stable/3679467
        
         | josephg wrote:
         | Modern electric pianos support changing from 12TET to other
         | things. I wonder how it would sound to have an electric
         | instrument retune itself throughout a performance as the key
         | changes. Would it be worth the hassle?
        
       | smlacy wrote:
       | Another possible explanation, which I'm surprised the author
       | didn't go through is the "Circle of Fifths" which basically says:
       | 
       | Since Fifths sound so great, why not just keep doing that? When
       | we get to the next octave, then come back down. If we get to a
       | place that's "pretty darn close" to another note, then stop. The
       | Python explanation looks like:                 f = 440       for
       | i in range(13):           print(i,f)           f = f * 3/2
       | if f > 880: f=f/2.0            0 440       1 660.0       2 495.0
       | 3 742.5       4 556.875       5 835.3125       6 626.484375
       | 7 469.86328125       8 704.794921875       9 528.59619140625
       | 10 792.894287109375       11 594.6707153320312       12
       | 446.00303649902344
       | 
       | Note that after exactly 12 steps, we're back at 446 which is
       | "pretty close" to 440. So, we take this set of notes, sort them,
       | and just jigger it a little bit to get the 12 notes we know
       | today.
        
         | ledauphin wrote:
         | are the post and your comment not mathematically equivalent
         | statements?
        
           | elihu wrote:
           | No, the article is essentially pointing out that the 12th
           | root of two to the seventh power is really close to 1.5,
           | whereas the comment you're replying to is saying that if you
           | raise 1.5 to the 12th power, you get really close to a power
           | of 2.
           | 
           | The former is more interesting when it comes to how music
           | works psychoacoustically: the interval of a perfect fifth is
           | fundamental to almost all music. Whereas the "circle of
           | fifths" is more of a convenience that makes it easier to
           | think about keys. Few songs would ever traverse the whole
           | circle and come back to where it started, and if you stick
           | with strict just intonation there is no circle of fifths
           | anyways. (Maybe you could better call it a "spiral of fifths"
           | or something.)
        
           | smlacy wrote:
           | Its the use of the musical concept of Fifths that's the key
           | here: We just derive the notes from what sounds good, not
           | what makes sense mathematically? I'm just using Python to
           | mirror the author's analysis -- you can derive "12 notes"
           | pretty much just by using your ear and listening to the
           | Fifths.
        
             | dwringer wrote:
             | A perfect fifth is just 150% (3/2) the frequency of the
             | root, just as an octave is 200% (2/1). "What sounds good"
             | is in a certain sense based on the harmonic series, and in
             | that sense it is equivalent to what makes sense
             | mathematically.
             | 
             | A problem is that if you stack perfect fifths to get 12
             | notes then they won't sound in tune with each other across
             | different keys. It's this issue which forms the crux of the
             | linked post.
        
         | layer8 wrote:
         | In other words, 1.5^12 = 129.746... [?] 2^7.
        
         | gnulinux wrote:
         | It's worth mentioning that stacking fifths this way creates
         | something pretty close to an octave, but it's still noticeably
         | different from an octave. The difference between an octave and
         | 12 fifths is called "Pythagorean comma", it's about 23.46 cents
         | and it'll be obvious to all humans who don't have a
         | speech/hearing impediment, even if you were never musically
         | trained. (It's believed humans are sensitive to small intervals
         | like this because it's required to process spoken human
         | language). Traditionally, it's considered anything more than a
         | synctonic comma (i.e. 21.51 cents) will feel different to even
         | untrained ears. (but of course, this is just the theory, in
         | reality there is some small variance between humans,
         | background, culture etc).
         | 
         | https://en.wikipedia.org/wiki/Pythagorean_comma
         | 
         | This is pretty significant to mention, because even though 12
         | fifths are "very close" to an octave [1], they're far apart
         | enough that no one will feel an octave. In music, near misses
         | like this are very significant since they cause the feeling of
         | harmonic "dissonance". Since 12 fifths is a _very_ dissonant
         | interval (since it 's so close to an octave but still
         | noticeably out-of-tune) Western music developed techniques
         | (such as well-temperament, equal temperament etc) to make sure
         | this "error" is blend in. We achieve this by changing other
         | notes ("tempering") ever so slightly so that critical intervals
         | like fifths (or in other cases thirds etc) are stable. Other
         | cultures, such as classical Indian music, have their own way
         | dealing with Pythagorean comma! Since music is a universal
         | phenomena found in all cultures, but it doesn't manifest the
         | same way in all cultures (e.g. not all cultures give the same
         | kind of emphasis to pitch or harmony Western music gives)
         | various cultures developed their own different and interesting
         | ways to work around this "error".
         | 
         | [1] To be precise, we're referring to the difference between 12
         | fifths and 7 octaves. Since an octave is so consonant, sounds N
         | octave(s) apart feel "equal" albeit with different timbre.
        
           | jacquesm wrote:
           | Somewhere there is a perfect universe where 12 fifths form an
           | octave.
        
             | [deleted]
        
             | CobrastanJorji wrote:
             | You don't need a new universe. You just need a species that
             | hears sounds a little differently. We won't like listening
             | to their music, but it'll be really great for them.
        
               | gnulinux wrote:
               | This may or may not be true. In fact, it seems unlikely
               | to me your claim is true.
               | 
               | In nature, sounds produce harmonics i.e. when two objects
               | collide they usually create waves of frequency f, 2f, 3f,
               | 4f... in various (usually exponentially decreasing)
               | weights. It's very rare to find pure sounds (i.e. only f
               | frequency) in nature. The interval between f and 2f is an
               | octave apart (1:2 ratio); the interval between 2f and 3f
               | is a perfect fifth (2:3 ratio). So, when you actually
               | hear a sound, you actually hear an octave and a fifth
               | too, and how dominant this octave and fifth changes the
               | "timbre" of the sound. This way, you know the source of
               | the sound independent of the frequency. For example, both
               | a violin and a piano can produce the note A4 at 440Hz,
               | but anyone can easily determine if it's a piano or
               | violin. The reason is, when a piano produces A4, it
               | sounds not only just 440Hz but also 880Hz and 1320Hz
               | etc... too and the relative volume of 880Hz and 1320Hz
               | will be different than that of violin. Your brain
               | automatically interprets these volume weights as "timbre"
               | and the fundamental frequency 440Hz as "pitch".
               | 
               | Consequently, in order for your brain to be able to
               | process the timbre of a sound it needs to find octaves
               | and fifths between each fundamental note it hears. This
               | means there might be something universal about octave and
               | fifth (and other decreasingly consonant intervals such as
               | major third etc...). Maybe we "understand" music because
               | our brain is hard-wired to search for octaves and fifths
               | in all sounds, in order to analyze timbre and in order to
               | process spoken language. If this hypothesis is true,
               | maybe an alien species could have octave/fifth/major
               | third based music too! (if they have music at all, of
               | course)
        
               | jacquesm wrote:
               | There is also the shape of the individual waveforms to
               | take into account a piano has a more or less sinusoidal
               | wave and a violin is more of sawtooth (due to the
               | stickslip of the bow moving across the string(s)).
        
               | ajuc wrote:
               | You're saying the same thing - the combined sawtooth wave
               | is just the sum of all the sinus harmonics.
        
               | gnulinux wrote:
               | Is it not true that the shape of the waveform
               | (sinusoidal, saw-like etc) is created by the relative
               | weights of each harmonic? E.g. if you take any random
               | sound wave, Fourier-transform it, you'll find the weight
               | of each harmonic. Or are you saying there is a separate
               | quality to sound waves that can cause their shape to be
               | different even if each harmonic has the same relative
               | weight with respect to the fundamental?
        
               | abstrakraft wrote:
               | Yes, this quantity is the relative phase of the
               | harmonics, although the human ear is generally considered
               | to be insensitive to phase.
        
               | rrrrrrrrrrrryan wrote:
               | Eh, I think you'd need a new universe, as it's a pretty
               | basic principle of math:                 3^12 ~= 2^19
               | 
               | You can take two long strings of equal length (A & B),
               | and pluck them, and they'll make the same sound. Then you
               | can take scissors cut string A in half, and it'll sound
               | different. (This is an octave.)
               | 
               | Then you can cut string B into thirds, and it too will
               | sound different.
               | 
               | If you pluck both of your new strings at the same time,
               | you'll find they sound quite nice together (the
               | difference between these two is called a "fifth").
               | 
               | And after 12 rounds of cutting string B into thirds, and
               | 19 rounds of cutting string A in half, you'll happen to
               | have a string from each group that are _almost_ identical
               | in length and pitch.
               | 
               | But it won't line up exactly! They'll be about 1.4%
               | different in length, which roughly works out to a
               | quarter-semitone difference in pitch (i.e. 1/4th the
               | distance from one piano key to the next).
        
               | tshaddox wrote:
               | But who says the creatures need to perceive sound in such
               | a way that the harmonic series has sensory significance?
               | To be honest I've never seen a compelling evolutionary
               | explanation for why "hearing the harmonic series"
               | developed in the first place. It obviously seems useful
               | to be able to perceive sounds generated by (roughly)
               | harmonic oscillators, since those occur naturally for
               | various reasons, but why octave equivalence?
        
               | rrrrrrrrrrrryan wrote:
               | I don't think you need to imagine "creatures" - there are
               | humans on earth whose culture's music doesn't have the
               | concept of octaves, let alone fifths. All the real action
               | in their music is in its rhythmic complexity.
               | 
               | But my comment was in reply to this statement
               | specifically:
               | 
               | > Somewhere there is a perfect universe where 12 fifths
               | form an octave.
               | 
               | For this to be true, I think you'd indeed need a new
               | universe where 3^12 = 2^x, where X is a whole integer.
        
               | tshaddox wrote:
               | I'm not talking about explicit notions of octaves and
               | octave equivalence, although those do exist in very many
               | musical traditions and appear to be extremely widespread
               | in musical traditions where tones have names (if not
               | ubiquitous--I'm not aware of any exceptions). I was
               | referring to the claims that octave equivalence is in
               | some sense hard-wired in the human brain, or sometimes
               | claimed to be all or many mammalian brains. I'm not
               | qualified to evaluate these claims or even whether how
               | well-accepted they are among experts, but such claims do
               | seem to pop up all over the place when discussing music
               | perception.
        
             | inopinatus wrote:
             | I've heard there is a secret chord, that prophets play to
             | please their lords.
             | 
             | But if you care for music less than algebra, just know it
             | goes like this; the fourth, the fifth: the minor falls, the
             | major lifts.
        
             | thaumasiotes wrote:
             | That would have to be a universe in which the fundamental
             | theorem of arithemetic was false. Otherwise, the only way
             | to cross an interval that is an integer number of octaves
             | is to take steps that are also octaves.
        
               | coldtea wrote:
               | What the parent proposed doesn't require different math.
               | 
               | Just a species that hears out current slightly offset
               | divisions in 12-tet as perfect, as opposed to only
               | hearing integral ratios as perfect.
        
               | thaumasiotes wrote:
               | Viewing sound waves that don't synchronize with each
               | other as being better matched than sound waves that do
               | synchronize is less plausible than violating the
               | fundamental theorem of arithmetic. There's no element of
               | coincidence in whether two frequencies harmonize.
               | 
               | That hypothetical species wouldn't recognize two notes an
               | octave apart as being similar, so there would be no
               | reason to imagine a circle of fifths in the first place.
        
               | coldtea wrote:
               | > _Viewing sound waves that don 't synchronize with each
               | other as being better matched than sound waves that do
               | synchronize is less plausible than violating the
               | fundamental theorem of arithmetic_
               | 
               | Actually it's perfectly plausible. People couldn't
               | imagine others enjoying hearing a tritone -- and nobody
               | in 1800 would imagine we'd enjoy listening to punk, hip
               | hop, or Death Metal, and yet, millions do. We can surely
               | consider a race that doesn't require intervals to
               | absolutely synchronize.
               | 
               | > _That hypothetical species wouldn 't recognize two
               | notes an octave apart as being similar, so there would be
               | no reason to imagine a circle of fifths in the first
               | place._
               | 
               | Note how I said that this imagined alien race would
               | consider the "divisions in 12-tet as perfect". Note how
               | those _do_ include a perfect octave, that we already
               | recognize as such. The alien race wouldn 't change that,
               | they'd just need to also consider perfect the slightly
               | off ratios in 12-tet.
        
               | thaumasiotes wrote:
               | > Actually it's perfectly plausible.
               | 
               | No, for this to be plausible, you would need to have some
               | theory of why the two notes matched with each other.
               | There is no such theory; they have been chosen to be as
               | unmatched as possible.
               | 
               | > nobody in 1800 would imagine we'd enjoy listening to
               | punk, hip hop, or Death Metal
               | 
               | This is false.
               | 
               | >> That hypothetical species wouldn't recognize two notes
               | an octave apart as being similar
               | 
               | > Note how I said that this imagined alien race would
               | consider the "divisions in 12-tet as perfect". Note how
               | those _do_ include a perfect octave, that we already
               | recognize as such. The alien race wouldn 't change that
               | 
               | Sure. In that case, we can also imagine an alien race
               | that perceives all and only the light that fails to reach
               | its eyes.
               | 
               | Then again, perhaps being able to form a sentence
               | describing something doesn't guarantee that the situation
               | described is possible.
        
           | posterboy wrote:
           | I'm not comfortable with this first refering to a natural
           | human tendency and then a western harmony, which is pretty
           | much accquired, as if it were a natural consequence.
           | 
           | A simpler way to go about this is using the chromatic scale,
           | drawing multiples of C0 upto C8 so that C7 to C8 spans an
           | octave, and then fixing F according to a table of equal
           | temperament.
        
             | coldtea wrote:
             | > _I 'm not comfortable with this first refering to a
             | natural human tendency and then a western harmony, which is
             | pretty much accquired, as if it were a natural
             | consequence._
             | 
             | Well, western harmony is based on a set of natural human
             | tendencies formalized.
             | 
             | There are other ethnic music practices, also based on
             | natural human tendencies.
             | 
             | The parts that are acquired are built on top. But most/all
             | music practices (western or otherwise) start with natural
             | human tendencies, as their foundations.
        
         | frereubu wrote:
         | Fifths don't sound so great after a while. This tuning leads to
         | the dissonant "wolf interval" -
         | https://en.wikipedia.org/wiki/Wolf_interval - so it was largely
         | replaced by the well temperament -
         | https://en.wikipedia.org/wiki/Well_temperament - used by Bach
         | in _The Well-Tempered Klavier_.
        
         | jefftk wrote:
         | You're both describing two similar consequences of the same
         | mathematical fact: 2^(7/12) is close to 3/2:
         | 
         | * The reason that in their 12-note graph the red line very
         | nearly overlaps with the seventh green line is that
         | (2^(1/12))^7 is very close to 3/2.
         | 
         | * The reason that twelve fifths nearly make an octave --
         | (3/2)^12 is ~2^7 -- is that if you use 2^(7/12) to approximate
         | 3/2 then it's (2^(7/12))^12 which is exactly 2^7.
         | 
         | Since you're applying the approximation twelve times instead of
         | once, that also explains why we've gone from being off by 0.11%
         | to 1.4%.
        
         | tetris11 wrote:
         | (For those wanting to hear these frequencies:)
         | 
         | aplay -d 2 -r $freq
        
         | xchip wrote:
         | Eh eh as other people say, you have discovered the Pythagorean
         | scale, that is known to drift away slowly from the correct
         | frequencies, that's is why for a long time people didn't use
         | chords that overlapped octaves, because they sounded weird and
         | they called those evil chords
        
         | AndrewUnmuted wrote:
        
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