Hey everyone :) I'm planning on building a piano/keyboard which plays its notes by controlling old electronic devices, to make them move at a certain frequency. But my question is, how many devices will i actually need in order so play good songs on that piano? What's the maximum amount of notes that have been used in a song by a piano at the same moment? I'm not that skilled in playing piano (yet).
If you depress the damper/sustain pedal, you can play every note on the keyboard and have them sound simultaneously. A digital piano might also be able to sound multiple voices from one keystroke.
I have seen a performing piano player run the back of his hand/fingers up/down the keyboard at the end of a song, so playing most of the white keys or most of the black. The TV didn't show what his right foot was doing to the pedals.
My digital piano has 256 note polyphony and 88 keys. I think it can play 3 voices simultaneously from the keyboard. So this level of polyphony accommodates 3 voices played simultaneously (e.g piano, choir and harpsichord voices) with the damper/sustain pedal down.
Well that's an interesting question. The answer depends on the context I think.
If there is only one player, and he is only using his hands then I think the maximum that could be struck at the same time will be something like 12,13 or 14, although you rarely see this in most "regular" music. I can play six notes with one hand fairly easily and perhaps seven if I try hard.
Of course if we are using the sustaining pedal then we can get many more notes sounding at once, even though they have not been struck at the same time.
Some more modern pieces call for the performer to strike the keyboard with some sort of aid - usually a shaped board which fits over the keys. I seem to recall that there was supposed to be a piece which required one of these things that played every note at the same time (I might be mis-remembering that though).
Finally if there is more than one player - a duet for instance - then you can easily have 16+ notes simultaneously.
8-voice polyphony will get you a basic piano imitation.
32-voice polyphony may not be enough if you want to use the sustain pedal idiomatically!
You need to be wary of published specs. '64-voice polyphony' is not so impressive if each note uses 4 voices. 'Voice' and 'note' can get muddled up in advertising-speak!
If we move focus away from 'piano' to 'keyboard instrument', we managed to play a lot of music on the Prophet 5 (5-voice) and Yamaha DX7 (16-voice).
At a lower limit, if you can't have more than six, it's not going to be useful. Piano players can easily and often do play chords with three notes per hand or more. Additionally, there are some chord types, namely 13th chords, that will have six notes (if excluding the eleventh). An absolute minimum would be six, because five or lower cripples the capabilities of the instrument to make music. On the higher limit, for pop genres generally six is the upper limit anyway. Other genres, especially jazz, which uses many extensions at once, and neo-soul, whose chords double notes and pretty much add every note of a scale and then some, tend to break 10 notes simultaneously without a second thought. So I'd say that depending on genre, a minimum of 6-polyphony, and at most probably 20-polyphony to be safe.
The practical maximum is 10 because that's how many fingers you have. Yes you can use your palms and arms or lay a finger across two keys and some pieces call for an extreme amount of notes. Some other answers seem to have taken that word maximum to heart a bit too much considering that you're building a physical, electro-mechanical instrument where each extra voice comes at a premium.
So maybe the answers should focus more on this part:
But my question is, how many devices will i actually need in order so play good songs on that piano?
…rather than focusing on what are largely exceptional cases (smears, the songs with the absolute most simultaneous notes, etc).
One thing Emma touched on is the sustain pedal. I'd assumed you probably weren't using one given how I'm envisioning your project—it sounds similar to art projects where people have wired up hard drives and printers to vibrate. But if you are building in sustain that definitely changes things and you'll want more polyphony.
Lastly the ask yourself what genre you'd like to play because some will require more voices than others. But I think you'd be ok with 10 assuming no sustain pedal.
Also just about any tune could be simplified to fit whatever number of voices that you settle on. And since it sounds like you'll be the one playing it, it's only a problem if you mind having to do that.