[HN Gopher] Restoring and MIDI-Fying a Baby Grand Piano
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Restoring and MIDI-Fying a Baby Grand Piano
Author : jacquesm
Score : 172 points
Date : 2020-06-18 13:17 UTC (1 days ago)
(HTM) web link (jacquesmattheij.com)
(TXT) w3m dump (jacquesmattheij.com)
| dheera wrote:
| This in interesting. I've been wanting to make a neural piano
| synthesizer for an electronic keyboard that outperforms the
| sample-based stuff Yamaha and Kawai use. But getting labelled
| training data is a problem. Would be interesting to use a setup
| like this to amass loads of accurate training data about what
| inputs produce what waveforms!
|
| If the author is willing to mic up the piano properly with a good
| mic, and publish a few hours of uncompressed samples of piano
| playing along with the associated MIDI files -- it doesn't have
| to be good playing, but preferably better than "random" playing,
| it would be super cool to play with that data.
| jacquesm wrote:
| For another project (mp3->midi) I used a large number of piano
| midi files coupled with midi->wav conversion to give me a
| dataset like that. The original midi serves as labels for the
| audio.
| dheera wrote:
| Yep all the author needs to do is download a few hundred MIDI
| files, play them, and record the piano -- it would be an
| interesting dataset to play with.
|
| Most of even the top of the line digital pianos seem to get
| the resonances and cross-talk between the strings wrong in my
| opinion, and I think a neural net should possibly be able to
| learn the internal physics of the piano from enough samples.
| jacquesm wrote:
| Author here... Unfortunately there is a pretty busy road
| passing my house which would preclude miking the piano and
| getting meaningful results. Also: that's a _lot_ of
| combinations! But you are right, going this route should in
| theory give you a way to generate audio that comes much
| closer to the real interaction between the strings and the
| soundboard than the mixer step at the end of your typical
| digital piano. They all sound way too clean.
| 29athrowaway wrote:
| It turns out, depending on where you live, a piano may actually
| cost you nothing.
|
| The free stuff section of craigslist has many pianos, for some
| weird reason. Just go to "For sell" > "Free stuff" and search
| "Piano".
| jacquesm wrote:
| Yes, this is true. Many people that move want to get rid of
| their pianos, they are heavy and need some pretty specialized
| gear if they are not on the ground floor to move them. But
| grand pianos are usually worth at least something simply
| because people like them as furniture even if they can't play
| at all.
|
| CL isn't very active here in NL as far as I know but
| Marktplaats has lots of listings and there are also quite a few
| thrift stores that will sell pianos for very little money. Even
| so, you can expect about a 100 euros or thereabouts to move
| one.
| 29athrowaway wrote:
| True, the moving part is not free. Also, some may not be in
| perfect condition and may need tuning or more costly work,
| but certainly not $10,000. But, as a starting point, it's
| something.
|
| I did a quick search and I could find baby grand pianos and
| grand pianos for free.
|
| Cool article, I enjoyed the demo.
| jacquesm wrote:
| > I did a quick search and I could find baby grand pianos
| and grand pianos for free.
|
| Neat, that would be worth watching to see if anything nice
| and worth restoring comes by. Even so, plenty of old pianos
| are simply so worn out that any work on them is probably
| lost effort, this one was a border case. For instance,
| replacing the 'dead' bass strings would be way too
| expensive. A useful trick is that you can rotate them 90
| degrees to get some more life out of them (because they've
| been struck by the hammer at the bottom they typically
| vibrate in only one direction!), but there is a fair chance
| the string will break when you re-tension it after rotating
| it.
| caiobegotti wrote:
| That's some fantastic work, a job well done for sure! I couldn't
| help to notice some texture on the new wood paint and I wondered
| why the author simply did not restore the original beautiful wood
| and went instead for that hard brownish painted tone. It's as if
| the sanding wasn't fine enough in grit too, because lacquering
| with polishing is supposed to give you almost a mirror-like
| result (that's all based on a single indoor picture of course,
| sorry). Congrats again to the author!
| jacquesm wrote:
| The case was extremely damaged, and not made of real wood but
| of plywood with veneer on top.
|
| The veneer layer had already been sanded at least once and was
| super thin in places and of course that is where the bulk of
| the water damage was. In the end in a few places there was only
| a super thin layer of veneer left and in one or two places none
| at all. Wood grain filler was used to make the first layer more
| even, then three layers of red stain were added and finally two
| layers of high gloss transparent.
|
| I would have loved to use only two layers of stain but the wood
| left underneath just wasn't good enough for that anymore.
| Anyway, so it isn't quite as dire as you make out from the pics
| but it also could have come out a lot better if there was more
| to start with. In person it looks quite good, especially the
| combination of brass with the red stain.
| caiobegotti wrote:
| Thanks for the detailed follow-up!
| jacquesm wrote:
| You're welcome. In fact, the case was so bad, and the
| action so messed up that I thought it might end up a total
| loss. I love recycling other people's junk into things that
| are nice again, this is probably the best example of that
| so far.
| [deleted]
| js2 wrote:
| This is amazing. I'm going to show this to my tuner who also does
| restorations, but I know that he's going to shake his head that
| anyone would do this much work on that piano.
|
| What did you do with the G3? Do you now have two baby grands?
| jacquesm wrote:
| It is still there, sitting right next to the other. So yes, and
| a G3 is 180 so not quite a baby, it is huge next to the other
| one. This is - obviously - a matter of some discussion as was
| turning the living room into a woodshop for the last month or
| so ;)
| dharma1 wrote:
| Awesome project. The main difference I can see is that the
| solenoids on Disklaviers are very quiet.
|
| I've got a mid-80's U3 Disklavier I bought a couple of years ago,
| one with a floppy disk controller. It was about PS4k, bought it
| from a dealer who imports them from Japan. I love it - the
| strings are longer than a standard upright, but doesn't take as
| much space as a baby grand.
|
| I only have one wish for it - that someone would make a new (
| ideally open source) controller unit that works with old
| Disklaviers!
|
| The unit has midi I/O but has about 500ms of latency on playback
| - still very nice as a party trick and for recording ideas - but
| somewhat limits the usability with a sequencer.
|
| Still, it's pretty mad I am using a Japanese robot piano from
| nearly 40 years ago that still works exceptionally well.
| jacquesm wrote:
| Those solenoids are super quiet because of how they are
| designed, the top is made of rubber with a felt insert, the
| weight also has a felt layer at the top so when it strikes
| upwards it can so so forcefully but quietly, without the
| 'clack' associated with solenoids. Finally, the shaft is super
| thin (2mm) and runs in a nylon guide for reduced friction, and
| there is a small spring in between so that when it drops it
| gets slowed down a bit.
|
| As for the 500 ms, there is a setting on the wagon that allows
| for realtime during playback.
| qrv3w wrote:
| Totally amazing. The work you did seems tortuous but its looks
| like its paid off! What a brilliant machine you have now, with so
| many possibilities, on top of sounding really really good.
| moralestapia wrote:
| Very nice read, thanks.
|
| It made me recall a nice memory as well. A while ago we (me and
| some friends) were helping out in some hurricane struck area. We
| were basically cleaning and throwing away stuff. In one house
| there was a Disklavier that was ruined and almost completely
| covered with mud. We asked the owners if we could keep it and
| they were like 'sure yeah just take it from here'. We spent a
| good month just playing with it, taking out everything, then
| trying to put it back together. Aside from the physical keys,
| nothing was salvageable but it was a very fun experience.
| jacquesm wrote:
| Did you have a good look at the hammer/keyboard sensors? Those
| are works of art.
| [deleted]
| cs702 wrote:
| Fabulous work. The kind of project that I would have never heard
| about... if it weren't for HN.
|
| Supper happy to see this at the top of the front page.
|
| Thank you for sharing.
|
| On a less serious note, you could totally _freak out_ your future
| house guests with stories about a ghost that occasionally plays
| the piano at night!
| sixothree wrote:
| I like the mix of postings on HN.
|
| There are enough personal projects out there to absolutely
| flood this site and it seems on weekends there are more of them
| (maybe my imagination). But still the site doesn't get flooded.
| jacquesm wrote:
| > On a less serious note, you could totally freak out your
| future house guests with stories about a ghost that
| occasionally plays the piano at night!
|
| Hm... that's some inspiration I may not be able to ignore.
| tpurves wrote:
| I misread this title as a MIDI capable 'flying' Baby Grand Piano.
| So was mildly disappointed, but OTOH that could be a whole other
| level of drone-art/aeronautical/electro-mechanical project for
| some enterprising hacker out there?
| jacquesm wrote:
| With the weight of your average piano (700 pounds or
| thereabouts) that would require some major engineering, you're
| looking at something the size of a regular helicopter to lift
| it.
| DonHopkins wrote:
| Q: What do you get when you drop a piano down a mine shaft?
|
| A: A flat minor.
| ogre_codes wrote:
| Thank you. I've seen this article on HN a couple times this
| morning and each time I briefly think "A flying grand piano,
| that sounds awesome!".
| jmportilla wrote:
| Incredible work!
| bsimpson wrote:
| My parents bought a used Disklavier in the 90s that had mostly
| just been furniture, since floppy disks went obsolete.
|
| A few years ago, my dad found a Bluetooth adaptor for it, but the
| process of streaming songs to it was a convoluted mess that
| involved downloading MIDIs, putting them in Dropbox, opening them
| on an iPad in a different app, etc.
|
| I was home for the holidays that week, so I threw together a
| Chrome extension that streams songs with WebMIDI:
|
| https://github.com/appsforartists/midicast
|
| Super fun project. Far from perfect, but it's neat to
| programmatically control a musical instrument.
|
| Gave me a chance to try the Cycle architecture too, which works
| really well for a Chrome extension. Chrome extensions are all
| about message passing between various contexts. Cycle's reactive
| model abstracts all that away, so you don't have to think about
| which piece is running where - you just describe how data gets
| transformed as it flows through the system.
| necrotic_comp wrote:
| Nice work ! Your solution is much better, but I'd be remiss if
| I didn't mention that floppy drive emulators also exist and are
| currently in use for people who are using old samplers -
| https://www.amazon.com/SFR1M44-U100K-Floppy-Drive-
| Emulator-E....
| dharma1 wrote:
| This is great, thanks for making it! I've got a bluetooth midi
| adaptor with my old Disklavier too - there is an iOS app for
| streaming midi files into it but it's got a monthly
| subscription. Your Chrome extension looks perfect.
| jacquesm wrote:
| This whole 'software as a service' thing has really gone too
| far when things like drivers are being sold on a subscription
| base.
| jacquesm wrote:
| Neat project!
|
| Disklavier control boxes also have MIDI in, and you can get
| fairly cheap USB->Midi adapters. That way you can sidestep the
| bluetooth link if you want to use a computer to drive it.
| DenisM wrote:
| This is some serious commitment to the cause. Hats off, sir.
| inetsee wrote:
| This is an impressive amount of work, especially considering how
| much modification had to be done to the solenoids.
|
| For me, the best part was the link to the PianoBooster software
| http://pianobooster.sourceforge.net/ That software looks like a
| great way to help newbies overcome the early hump in learning to
| play the piano.
| jacquesm wrote:
| Pianobooster is awesome, it is the most patient piano teacher
| you can imagine. I've modified it a bit to give me more
| statistics and to more intelligently split left / right hand
| parts. The original tends to assign notes based on a pretty
| rigid rule and I changed it so it uses some geometrical clues
| about what handspan you can expect to better assign the notes
| to the individual hands.
| bluGill wrote:
| Can you open a pull request at
| https://github.com/captnfab/Piano Booster someone has given
| the project new life in the past year (it was dead for about
| 5)
| jacquesm wrote:
| Ah cool. I tried to reach the original author but he did
| not respond. Thank you for the pointer.
|
| Pianobooster has an interesting internal architecture, it
| works completely in 'streaming' fashion which makes it
| quite hard to operate on the input files, you can't really
| look ahead because the whole file is never entirely in
| memory. It took me a while to get my head wrapped around
| that, it is so completely different from how I would have
| approached that particular problem. I can see some
| advantages to this way of doing things. Another interesting
| point is that it has a lot of the business logic in two
| places, one where it deals with the audio part of things
| and one where it deals with the visual part. These then
| sync up again at the currently playing note(s).
|
| Anyway, regardless, it is an awesome project and I'm super
| happy to see that someone has taken up the mantle.
| FatalLogic wrote:
| How much control do you have with the solenoids, and the hammers?
| Is it just control of the velocity of strike, or is it possible
| to have positional control of the hammer?
|
| If you could control the position, maybe you can create some
| interesting tonal effects that a human pianist could not achieve,
| by holding the hammer close to the string to partially damp it
|
| (Similar to what guitarists can do)
| jacquesm wrote:
| Positional control of the _keys_ (not the hammers) is possible
| but the solenoids get very hot. Strike velocity is not
| proportional, I will have to add some filtering to ensure that
| loud passages don 't break a hammershank.
|
| As for the tonal effects, you can't really manipulate a piano
| hammer like that through the action, and this mechanism still
| uses the normal action the way it is intended, only it strikes
| from below the pivot rather than above, so at the back of the
| key. The whole function of the piano action is to give a
| uniform response to uniform input so the hammer can only
| describe a particular arc with a speed relative to the force
| with which the key is struck. You can't 'freeze' the hammer at
| the top of that arc, it will just fall back down until it gets
| caught by the back-checks.
|
| What you can do and what would be impossible with just one
| pianist and just your fingers is to strike key combinations
| that would be otherwise impossible. For instance to make a
| chord that uses more than the normal number of fingers or that
| would require extreme contortions or more than two hands.
| FatalLogic wrote:
| Then you could make some interesting effects by using each
| human key strike to trigger extra keys, such as one or two
| octaves higher or lower, or something more colorful like a
| note one fifth higher at reduced velocity, or time delayed
| perhaps
|
| edit - just noticed that it seems you hadn't yet been able to
| get the key sensors working, only the output
| rzzzt wrote:
| The Windows 3.1-era Band-in-a-box had a feature (and
| probably still has, if that software is still around) that
| allowed playing along a pre-programmed chord progression in
| different styles, which always produced a harmony that
| matched the current chord with a a single key press. You
| could play in the style of eg. Erroll Garner, even if you
| only knew how the "bare" melody of the song goes.
| davio wrote:
| That was amazing "AI" for the 1990s. It would play never-
| ending bebop solos that were pretty legit. The author
| must have been a well-versed musician and programmed in
| the standard licks from the jazz vocabulary.
| jacquesm wrote:
| Do you know which software this was?
| DonHopkins wrote:
| My friend and serial colleague David Levitt wrote his PhD
| thesis about applying AI to Jazz improvisation at MIT
| EECS in 1981, titled "A Melody Description System for
| Jazz Improvisation". His PhD advisor was Marvin Minsky.
|
| https://dspace.mit.edu/handle/1721.1/32122
|
| https://dspace.mit.edu/bitstream/handle/1721.1/32122/0827
| 896...
|
| >A Melody Description System for Jazz Improvisation
|
| >This thesis describes a program which embodies several
| computational aspects of music improvisation and
| composition. Given an initial melody and harmonic
| outline, the program produces a single voice of
| improvisation. While the improvisation is intended to
| resemble a jazz (eg. "swing" or "bebop") solo, the
| program's descriptive techniques reflect computational
| elements common to a range of tonal music. These include
| building up phrases from partial descriptions,
| recognizing interesting features, and re-examining a
| remembered phrase to produce a variation in a new
| context. Throughout, the program uses various ideas of
| similarity, repeated patterns, defaults, and mutually
| constraining structures, trying to anticipate the
| audience's expectations to make the improvisations
| understandable and interesting.
|
| David also developed a Mac app called "Harmony Grid", and
| a visual programming language called "Hookup" for
| programming midi and hardware and software like the
| Macromedia Director player library. David shared an
| office at the MIT AI Lab's "Music Hacker's Hangout" with
| Miller Puckette, who developed Max/MSP and PD. He later
| worked on another MIDI-driven visual programming language
| developed at VPL, Body Electric aka Bounce.
|
| https://link.springer.com/chapter/10.1007/978-3-642-58126
| -7_...
|
| >Representing Musical Relationships in the Harmony Grid
|
| >One of the most difficult questions of multimedia design
| is when is it appropriate to use a given medium or mode
| of interaction. Sometimes the answer is not as obvious as
| it might seem. For instance, a program which manipulates
| music obviously has to be capable of playing music,
| presenting auditory information, but to what extent
| should the interface to the program be an auditory one?
| This chapter describes one such program which teaches
| about music, but with which the student interacts using a
| two-dimensional spatial representation of musical
| relationships. In other words a cross-modality mapping
| occurs. This kind of mapping appears to be especially
| successful because variants of it have been applied to
| good educational effect more than once. Indeed, Chapter
| 12 describes a successful use of a different but closely
| related cross-modality mapping. A very interesting and
| open question is: why is this mapping appropriate, where
| others may not be?
|
| >1. Introduction
|
| >The Harmony Grid was developed to help musicians and
| non-musicians visualize harmonic relationships in the
| traditional western 12-semitone chromatic system. It
| spatially represents some of the thinking that goes on
| when a composer or improvisor describes a melody or chord
| progression: 'Now the chord root is descending on the
| circle of fifths; now the melody is ascending . .
| chromatically; now it's descending on the whole tone
| scale~ .. ' and so on. Articulately or not, we create
| these structures when we make and appreciate music -
| dynamic ways of thinking about notes as 'near' each
| other. The Harmony Grid lets us visualize these musical
| relationships as adjacencies in fields of spatial
| intervals, displayed as two-dimensional grids.
|
| Here he is demonstrating his "Music Box" software and
| talking about his research at the MIT AI Lab and Atari
| Cambridge Research Lab:
|
| https://www.youtube.com/watch?v=ocwsVkqEKys
|
| I posted a link to old photo of David in this comment:
|
| https://news.ycombinator.com/item?id=8860722
|
| More about Hookup and Bounce:
|
| https://news.ycombinator.com/item?id=22788773
| rzzzt wrote:
| I think we were both talking about PG Music's (literal)
| "Band-in-a-Box": https://en.wikipedia.org/wiki/Band-in-a-
| Box
|
| Happy to read that it's still being updated.
| jacquesm wrote:
| Thank you!
| catblast wrote:
| There's a relatively old FOSS "band-in-a-box" program:
| https://www.mellowood.ca/mma/
| jacquesm wrote:
| Neat example of this (someone posted this as a response
| on Twitter):
|
| https://www.youtube.com/watch?v=bvMW71BJofc
| jacquesm wrote:
| Church organs have such functionality, typically limited to
| activating octaves higher and lower than the rank played.
| Quite impressive given that that all works mechanically.
|
| And yes, that would require input, but I will be working on
| that next and I can already play using a digital keyboard
| on the piano (which gives a very eerie effect), and that
| way I can do such stuff.
| bondarchuk wrote:
| https://www.youtube.com/watch?v=oPG-VhU6Kiw
|
| You might like this.
| nitrogen wrote:
| Nice! I have an old Wurlitzer electric that I have been wanting
| to restore and MIDIfy. This gives me hope that the requisite
| modifications to a Disklavier or Pianodisk setup might actually
| be possible.
| jacquesm wrote:
| That should not be too hard, the thing to look for would be an
| Arduino based MIDI project that you could adapt for your
| purposes.
| mkl wrote:
| Does it have power limitations on the number of simultaneously
| active solenoids? A friend ran into that problem. Can it play
| Circus Galop? https://www.neatorama.com/2012/02/03/unplayable-
| piece-used-t...
| jacquesm wrote:
| It will be more than happy to activate 20 solenoids at once,
| which is pretty loud. In practical music you'd use the sustain
| pedal if you wanted more/longer notes held.
|
| I don't feel like stressing it to the point where it might
| break using 'black MIDI' or some equivalent, the power supply
| is 35 years old and might give up the ghost.
| jancsika wrote:
| I imagine the demo to be playing a Nancarrow Player Piano Study
| like no. 36 or 37 (or Tango?).
|
| No. 36 is a 4 part canon where each part moves in a different
| tempo, forming a tempo ratio 17:18:19:20. Imagine taking a Bach
| fugue and applying a skewX or perhaps a Gaussian blur to it. All
| the voices converge roughly in the middle of the piece to create
| a striking texture unplayable by humans.
|
| No. 37 is a twelve-voice canon with an esoteric relationship
| among the voices (based on pitch-interval ratios of a particular
| scale from a book by Henry Cowell.) It's basically a series of
| little episodes where he trains the listener to focus on the
| texture-- because what else could you focus on in a twelve-voice
| canon? Then at the end, he introduces this low, enigmatic
| ricercare tune that builds into this enormous, sprawling texture
| of harmonic and melodic surprises, like aliens slowly descending
| upon Eisenach 300 years too late to find their lost ancestor.
|
| Trimpin made MIDI recordings of the 50+ player piano etudes back
| in the 90s.
|
| And if copyright weren't full of anachronistic concepts, one of
| them would be the Lenna of MIDI piano demos in the 21st century.
|
| Unfortunately, copyright is still full of anachronistic concepts.
|
| So instead you get an early Debussy piece. And where you would
| have said, "Holy shit, that is wild!" to a demo that properly
| shows off all the work the author put into MIDI-fying a baby
| ground, you instead say, "Hm, neat."
| cdelsolar wrote:
| this is just incredible.
| yc-kraln wrote:
| Grats on the cheap grand! I bought a similarly inexpensive piano
| in a similarly decrepit condition before Covid, I've been meaning
| to MIDI-fy it as well. Thanks for the inspiration!
| jacquesm wrote:
| Cool, let me know if I can help somehow. I've learned a lot
| that I would do better on another run.
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(page generated 2020-06-19 23:00 UTC)