> The study scientifically confirmed that professional pianists can manipulate timbre mid-performance through subtle key movement differences.
I'm a trained pianist myself and I have a PhD in science. The "timbre" is relative to the speed a key is pressed and the position of three pedals of a grand piano. But this insight is trivial and doesn't require a "scientific study".
The fundamental understanding of piano mechanics is well-known: once the hammer escapes from the action mechanism (just before striking the string), the final hammer velocity is the only physical parameter that determines the string vibration and resulting tone. This is known as the "single variable hypothesis" and has been supported by acoustic physics research. The final hammer velocity is thus the only physical parameter controlling the intensity and the sound of an isolated piano tone, independent of the intrinsic acceleration pattern of the key.
The study's claim about "acceleration at escapement" is particularly problematic from a physics standpoint, since escapement is precisely the moment when the hammer detaches from the key mechanism and begins free flight to the string. What matters after escapement is the hammer's velocity during that free flight, not how it got there. The study does not clearly explain the acoustic mechanism by which different key accelerations would produce different string vibrations if final hammer velocity is controlled.
Anyone who is sufficiently interested to listen to a classical piano performance understands this. The original name for the piano was 'pianoforte', it was a novelty that it could be played soft or strong in contrast to instruments like the harpsichord.
I also don't understand what the breakthrough in this paper is supposed to be. I pointed out to the lead author that velocity-switched multisampling libraries have been available commercially for decades, but didn't receive any response. Seems like a vanity/prestige publication to me, perhaps a way for Sony to advertise the high-speed capabilities of its cameras.
My personal suspicion as to how this stuff matters for the timbre of a piano is that there are maybe two mechanisms aside from the obvious one (velocity of the hammer):
1. Subtle movements of the damper, which is linearly linked to the key. You can hear this interference with the string if you get the string loudly and don't completely release the key/pedal.
2. Some second-order effects that alter the post-escapement flight of the hammer. There is still some friction in there, and most piano actions have a lot of wood parts that can flex a little.
I sort of doubt #2 there, honestly.
Another thing you learn as a pianist is that literally nothing matters for the sound except what happens at the point of contact between the hammer (and the damper) and the string. If you want to unravel piano timbre, you should worry about that.
The general vocabulary for describing timbre is limited and highly imprecise. There are many ways in which a passage of music could be perceived as "bright" or "dark", even if the timbre is identical.
It might just be a translation issue, but the paper gives me the strong impression that the authors do not actually understand timbre.
> Another thing you learn as a pianist is that literally nothing matters for the sound except what happens at the point of contact between the hammer (and the damper) and the string. If you want to unravel piano timbre, you should worry about that.
Heh, my piano teacher was pretty convinced that you could control timbre independent of amplitude.
You definitely can affect timbre of a piano string by crafting how you hit the key, but you can't do it with juju that doesn't affect how forces are applied to the string.
You sort of can! For example, by loudly humming at the string, supplying extra energy in some frequencies but not others. (Or, less facetiously, by playing other notes.)
Well you have a point there, lol. Half-pedalling is really lovely in that way, where the dampers are off just enough to let inter-string resonance fill the sound out without the notes getting smudged.
Yeah, @Rochus is right. Once the action has passed the escapement, its entire point is that you lose all control, else you'd get thudding, reversing the point of the fortepiano's innovation.
That's not to say us pianists have other tricks up our sleeves though. Staccato, slightly delayed playing, damper pedal (which is not just binary but continuous), slower release of key (because you can slowly apply the damper giving it a slight ringing effect), tempo changes, and other techniques get you quite a broad range of feeling. It doesn't however mean that timbre is orthogonal to volume--they are coupled by velocity.
Also, this post doesn't go into methods, so I worry about lack of ABX testing, whether it's a single note or a piece, whether they could see the pianist, etc. Perhaps they addressed that in the paper that they'll publish...
Edit: another thought: why is this even using subjective listeners? You can just measure velocity and run an FFT to see whether they can make a timbre separate from volume and velocity.
This is probably negligible, but the hammer is not perfectly rigid. The tension in the stem at the time the hammer escapes and subsequent oscillations could also play a role.
This little morsel was coagulating in my mind as I was reading all of these comments. No idea what, if any, effect there would be, but it is a variable.
I'm not reading this as saying that pianists can manipulate timbre after the hammer is released, only that pianists can intentionally manipulate timbre with very fine motor control while playing, and listeners of all levels can hear the intended timbre.
Which is trivial, as you say. (The examples of bright/dark aren't encouragingly subtle.)
The article is very poorly worded and ambiguous.
It's not even clear if they were measuring acceleration at escapement directly at the hammer, or somehow inferring it from the key velocity.
It seems acc-escape is measuring how hard the pianist is exerting their fingers/arms, which plausibly indirectly affects the coordination and style of sound that they play, hence the appearance of a different timbre.
> I agree, can these scientists seriously go and do some real work?
This can be said about a lot of individual studies, but it leads to missing the wood for the trees. We need seemingly trivial studies because they accumulate towards a greater understanding of our world and ourselves.
Also you can’t have the big interesting surprise results unless you are testing something where the answer seems obvious. This study seems fine.
What makes this study flawed is that they had pianists performing actual pieces of music. Pianists will change their attack to express different tone qualities, sure. But this has more to do with your muscles being imprecise and not the physics of the hammer itself. You have to use a variety of arm, wrist, and hand movements to get the exact subtleties of volume and note spacing correct.
I am guessing the reason this went 100 years without being proven is because it was an argument against the player piano and not an actual question that needed proving? Any competent pianist can demonstrate that they do this and it is the reason the piano became the dominant keyboard instrument.
The discussion in the linked post is incomplete. Obviously with the use of pedals the pianist has some direct control over timbre. The real question is whether, without the use of pedals, a pianist can control timbre with any degree of independence from volume. The reason to suspect that they cannot is that the action of the piano actually releases the hammer before it strikes the string (otherwise depressing a key for a long time would mute the string with the hammer instead of sustaining the note). It stands to reason that the hammer's initial angular momentum in flight cannot encode separately a note volume and note timbre.
So the mystery is the opposite: given that a mechanical understanding of the piano suggests that the pianist has no control of note timbre, why does it appear that they are able to adjust note timbre? I have my own speculations about this question, but it is not taken up by the article [1] which in fact only speaks of 'perceived timbre.'
In my own opinion, for the reason already given, there is no magic by which timbre is controlled through pressing the key daintily or pressing it with gusto, given that identical volume is achieved in each case. However the sonic environment is very complex and the pianist has considerable control over it through the dampers' connection to the keyboard, independent from the pedals. The process of listening is also very complex. The sense experience of hearing a staccato note is not the same as the sense experience of hearing the first 0.05 seconds of a note that later turns out to be sustained, so even if in fact the state of the piano is identical between the two cases within those 0.05 seconds I may perceive the timbres as different as my brain integrates the whole staccato note into 'one sound' while the sustained note is received as a continuous tone diminishing in intensity.
Ultimately I find the argument that they do not control timbre convincing, and that the piano (sans pedals) allows for as much control over timbre as the harpsichord does over dynamic. But as it is a very expressive instrument there is an illusion that is present for performance that cannot be reproduced through isolated notes. It's not a bassoon.
Timbre seems to be a pretty wide idea. If defined as “character” or “quality”, I would question the definition of “character” if it is anything other than “perceived character”.
In that case, we can say that timbre of a piano can definitely be controlled separately from volume—as in, one can play a note with the same volume (to some precision), but different timbre—if nothing else then because a piano note does not really exist standalone, and the perceived character of a sound from a given key will always depend on what keys were played before and after, how they were played, etc., adding innumerable complex interplays between all the factors involved, even possibly including the movement of the pianist.
Describing this difference as an illusion may be meaningful in some contexts, I suppose, but they would be pretty narrow and it is not too different from classifying consciousness as illusion: perhaps it cannot be quantifiable in certain ways, yet in other (very concrete and important) ways it is more consequential than many things we can quantify.
In other words, so if you compare A then B then C vs. Z then Y then C (where B and Y could even be the same note, just played differently), you can have “the same” C as measured in separation from the rest[0], but which crucially would nevertheless have a different character in listener’s mind—which may well be subjective, but also practically most relevant, and evidently reproducible.
[0] If that is even possible, considering the tails of preceding notes would be audible.
It's trivial to set up an experiment where you kick a single key with a solenoid and record the result. You can apply different velocity curves to the solenoid and see if there's any variation in timbre.
There probably will be. We're used to thinking of key velocity as a constant, but the escapement mechanism is quite complex and isn't truly instantaneous. There's almost certainly some room for dynamic velocity variation in touch as the key goes down.
Likewise with short vs long notes. I suspect there's some unconscious variation in key release dynamics, which will have a subtle effect.
What you're talking about is the more complex musical effect of many keys at once, with complex variations in timing (intentional and unintentional slurring of chords), dynamics (intentionally highlighting some chord notes over others), and all of the resonant interactions between open strings, dampers, and the frame.
> It's trivial to set up an experiment where you kick a single key with a solenoid and record the result. You can apply different velocity curves to the solenoid and see if there's any variation in timbre
Absolutely. Most of my comment is arguing how it would be not really useful, though, because perceived timbre (a.k.a. the kind that matters) is by definition wholly subjective, influenced by surrounding notes, etc.
But if all you're worried about is subjective appear, why even worry about tracking key velocity? You might as well just have a bunch of people go to a piano concert.
Coming from a synth background I assumed that any timbre variation that pianists can achieve came about via envelope manipulation. That and possibly volume related overtone production I suppose.
To be honest, as a pianist and physicist I’m still sceptical. The only thing you can influence at a mechanical keyboard is the speed with which the hammer hits the strings because by the time contact happens the escapement mechanism has removed the connection between hammer and key. One cannot influence its weight, momentum, angle, etc. So if all there is is a single variable (speed of the hammer), I find it hard to believe that one can change timbre independently on its own.
In piano performance you often can hear the mechanical sound of the keys themselves as well as the breathing and humming noises from the pianist. Not to mention a performance will be played in an environment where environmental sounds will be correlated with the perception of timber and the pianists physical movements. I don’t see mention if they controlled for all these things.
eg: the Keith Jarrett / David Helfgott recording inversion, performances where you can often hear the notes of the piano over the sounds of the pianist.
But why would you not expect the speed to change the timbre? Lower speed = less force of the hammer hitting the strings = less chaotic excitation of the string during the attack phase = less distortion in the upper harmonics, as well as less sympathetic resonance.
I expect change in timbre, but not independent of intensity and all that changes with a difference in hammer speed.
If all they are saying is that there is a change in timbre tout-court, then it’s trivial. If they’re saying one can change the timbre while keeping the intensity constant, then I have issues.
The purpose of most studies like this is not simply to establish a binary yes or no, but to measure, quantify and explain how something works in more detail than is currently known.
People knew that you would die if you were kept from breathing, but they didn't really know why that was, nor did they know the exact action by which breathing even occurred postulating that it air entered the body through the skin, or perhaps air somehow was necessary to cool the heart which at the time was theorized to be where all thought occurred.
You don't even have to know how to play a piano, just be allowed to touch one, to realise that hitting the keys differently will produce slightly different sounds.
> The study scientifically confirmed that professional pianists can manipulate timbre mid-performance through subtle key movement differences.
I'm a trained pianist myself and I have a PhD in science. The "timbre" is relative to the speed a key is pressed and the position of three pedals of a grand piano. But this insight is trivial and doesn't require a "scientific study".
The fundamental understanding of piano mechanics is well-known: once the hammer escapes from the action mechanism (just before striking the string), the final hammer velocity is the only physical parameter that determines the string vibration and resulting tone. This is known as the "single variable hypothesis" and has been supported by acoustic physics research. The final hammer velocity is thus the only physical parameter controlling the intensity and the sound of an isolated piano tone, independent of the intrinsic acceleration pattern of the key.
The study's claim about "acceleration at escapement" is particularly problematic from a physics standpoint, since escapement is precisely the moment when the hammer detaches from the key mechanism and begins free flight to the string. What matters after escapement is the hammer's velocity during that free flight, not how it got there. The study does not clearly explain the acoustic mechanism by which different key accelerations would produce different string vibrations if final hammer velocity is controlled.
> But this insight is trivial and doesn't require a "scientific study".
In my opinion, the insight is this:
> express in piano playing were perceived as intended by both pianists and musically untrained individuals
Obviously pianists have known this for more than a century. But do average listeners hear the same "thing"? It's a question worth asking.
Anyone who is sufficiently interested to listen to a classical piano performance understands this. The original name for the piano was 'pianoforte', it was a novelty that it could be played soft or strong in contrast to instruments like the harpsichord.
I also don't understand what the breakthrough in this paper is supposed to be. I pointed out to the lead author that velocity-switched multisampling libraries have been available commercially for decades, but didn't receive any response. Seems like a vanity/prestige publication to me, perhaps a way for Sony to advertise the high-speed capabilities of its cameras.
My personal suspicion as to how this stuff matters for the timbre of a piano is that there are maybe two mechanisms aside from the obvious one (velocity of the hammer):
1. Subtle movements of the damper, which is linearly linked to the key. You can hear this interference with the string if you get the string loudly and don't completely release the key/pedal.
2. Some second-order effects that alter the post-escapement flight of the hammer. There is still some friction in there, and most piano actions have a lot of wood parts that can flex a little.
I sort of doubt #2 there, honestly.
Another thing you learn as a pianist is that literally nothing matters for the sound except what happens at the point of contact between the hammer (and the damper) and the string. If you want to unravel piano timbre, you should worry about that.
The general vocabulary for describing timbre is limited and highly imprecise. There are many ways in which a passage of music could be perceived as "bright" or "dark", even if the timbre is identical.
It might just be a translation issue, but the paper gives me the strong impression that the authors do not actually understand timbre.
> Another thing you learn as a pianist is that literally nothing matters for the sound except what happens at the point of contact between the hammer (and the damper) and the string. If you want to unravel piano timbre, you should worry about that.
Heh, my piano teacher was pretty convinced that you could control timbre independent of amplitude.
You definitely can affect timbre of a piano string by crafting how you hit the key, but you can't do it with juju that doesn't affect how forces are applied to the string.
You sort of can! For example, by loudly humming at the string, supplying extra energy in some frequencies but not others. (Or, less facetiously, by playing other notes.)
Well you have a point there, lol. Half-pedalling is really lovely in that way, where the dampers are off just enough to let inter-string resonance fill the sound out without the notes getting smudged.
That explains Glenn Gould
Yeah, @Rochus is right. Once the action has passed the escapement, its entire point is that you lose all control, else you'd get thudding, reversing the point of the fortepiano's innovation.
That's not to say us pianists have other tricks up our sleeves though. Staccato, slightly delayed playing, damper pedal (which is not just binary but continuous), slower release of key (because you can slowly apply the damper giving it a slight ringing effect), tempo changes, and other techniques get you quite a broad range of feeling. It doesn't however mean that timbre is orthogonal to volume--they are coupled by velocity.
Also, this post doesn't go into methods, so I worry about lack of ABX testing, whether it's a single note or a piece, whether they could see the pianist, etc. Perhaps they addressed that in the paper that they'll publish...
Edit: another thought: why is this even using subjective listeners? You can just measure velocity and run an FFT to see whether they can make a timbre separate from volume and velocity.
This is probably negligible, but the hammer is not perfectly rigid. The tension in the stem at the time the hammer escapes and subsequent oscillations could also play a role.
That's a fair point, but I don't think that would make a split between timbre and amplitude.
This little morsel was coagulating in my mind as I was reading all of these comments. No idea what, if any, effect there would be, but it is a variable.
I'm not reading this as saying that pianists can manipulate timbre after the hammer is released, only that pianists can intentionally manipulate timbre with very fine motor control while playing, and listeners of all levels can hear the intended timbre.
Which is trivial, as you say. (The examples of bright/dark aren't encouragingly subtle.)
The article is very poorly worded and ambiguous.
It's not even clear if they were measuring acceleration at escapement directly at the hammer, or somehow inferring it from the key velocity.
It seems acc-escape is measuring how hard the pianist is exerting their fingers/arms, which plausibly indirectly affects the coordination and style of sound that they play, hence the appearance of a different timbre.
> this insight is trivial and doesn't require a "scientific study".
isn't this the case for many studies in the past decade? just confirming what we've known all along
News just in...bassists can alter timbre by touch!? I agree, can these scientists seriously go and do some real work? What an embarassment.
> I agree, can these scientists seriously go and do some real work?
This can be said about a lot of individual studies, but it leads to missing the wood for the trees. We need seemingly trivial studies because they accumulate towards a greater understanding of our world and ourselves.
Also you can’t have the big interesting surprise results unless you are testing something where the answer seems obvious. This study seems fine.
Wake me up when bassists can keep tempo and time ))
The study doesn’t have public access, but here’s a blog with some more details:
https://soranews24.com/2025/10/04/research-in-japan-proves-t...
What makes this study flawed is that they had pianists performing actual pieces of music. Pianists will change their attack to express different tone qualities, sure. But this has more to do with your muscles being imprecise and not the physics of the hammer itself. You have to use a variety of arm, wrist, and hand movements to get the exact subtleties of volume and note spacing correct.
How is arm movement affecting the tone without impact on the physics of the hammer?
I am guessing the reason this went 100 years without being proven is because it was an argument against the player piano and not an actual question that needed proving? Any competent pianist can demonstrate that they do this and it is the reason the piano became the dominant keyboard instrument.
The discussion in the linked post is incomplete. Obviously with the use of pedals the pianist has some direct control over timbre. The real question is whether, without the use of pedals, a pianist can control timbre with any degree of independence from volume. The reason to suspect that they cannot is that the action of the piano actually releases the hammer before it strikes the string (otherwise depressing a key for a long time would mute the string with the hammer instead of sustaining the note). It stands to reason that the hammer's initial angular momentum in flight cannot encode separately a note volume and note timbre.
So the mystery is the opposite: given that a mechanical understanding of the piano suggests that the pianist has no control of note timbre, why does it appear that they are able to adjust note timbre? I have my own speculations about this question, but it is not taken up by the article [1] which in fact only speaks of 'perceived timbre.'
In my own opinion, for the reason already given, there is no magic by which timbre is controlled through pressing the key daintily or pressing it with gusto, given that identical volume is achieved in each case. However the sonic environment is very complex and the pianist has considerable control over it through the dampers' connection to the keyboard, independent from the pedals. The process of listening is also very complex. The sense experience of hearing a staccato note is not the same as the sense experience of hearing the first 0.05 seconds of a note that later turns out to be sustained, so even if in fact the state of the piano is identical between the two cases within those 0.05 seconds I may perceive the timbres as different as my brain integrates the whole staccato note into 'one sound' while the sustained note is received as a continuous tone diminishing in intensity.
Ultimately I find the argument that they do not control timbre convincing, and that the piano (sans pedals) allows for as much control over timbre as the harpsichord does over dynamic. But as it is a very expressive instrument there is an illusion that is present for performance that cannot be reproduced through isolated notes. It's not a bassoon.
[1] https://www.pnas.org/doi/10.1073/pnas.2425073122
Timbre seems to be a pretty wide idea. If defined as “character” or “quality”, I would question the definition of “character” if it is anything other than “perceived character”.
In that case, we can say that timbre of a piano can definitely be controlled separately from volume—as in, one can play a note with the same volume (to some precision), but different timbre—if nothing else then because a piano note does not really exist standalone, and the perceived character of a sound from a given key will always depend on what keys were played before and after, how they were played, etc., adding innumerable complex interplays between all the factors involved, even possibly including the movement of the pianist.
Describing this difference as an illusion may be meaningful in some contexts, I suppose, but they would be pretty narrow and it is not too different from classifying consciousness as illusion: perhaps it cannot be quantifiable in certain ways, yet in other (very concrete and important) ways it is more consequential than many things we can quantify.
In other words, so if you compare A then B then C vs. Z then Y then C (where B and Y could even be the same note, just played differently), you can have “the same” C as measured in separation from the rest[0], but which crucially would nevertheless have a different character in listener’s mind—which may well be subjective, but also practically most relevant, and evidently reproducible.
[0] If that is even possible, considering the tails of preceding notes would be audible.
It's trivial to set up an experiment where you kick a single key with a solenoid and record the result. You can apply different velocity curves to the solenoid and see if there's any variation in timbre.
There probably will be. We're used to thinking of key velocity as a constant, but the escapement mechanism is quite complex and isn't truly instantaneous. There's almost certainly some room for dynamic velocity variation in touch as the key goes down.
Likewise with short vs long notes. I suspect there's some unconscious variation in key release dynamics, which will have a subtle effect.
What you're talking about is the more complex musical effect of many keys at once, with complex variations in timing (intentional and unintentional slurring of chords), dynamics (intentionally highlighting some chord notes over others), and all of the resonant interactions between open strings, dampers, and the frame.
That would be much harder to analyse.
> It's trivial to set up an experiment where you kick a single key with a solenoid and record the result. You can apply different velocity curves to the solenoid and see if there's any variation in timbre
Absolutely. Most of my comment is arguing how it would be not really useful, though, because perceived timbre (a.k.a. the kind that matters) is by definition wholly subjective, influenced by surrounding notes, etc.
But if all you're worried about is subjective appear, why even worry about tracking key velocity? You might as well just have a bunch of people go to a piano concert.
It could be possible that some research is not extremely useful while still making correct conclusions.
Also because loud. Most modern instruments have been evolving towards louder and louder variants.
What are you saying? i can't hear you!
I think that's good example (you can easy study yourself - as he did practice enough - mostly Chopin, as a child, then jazz):
Leszek Możdżer - Piano ( - Exploris, .. ) https://www.youtube.com/watch?v=QOicB0vcbf8&list=PLMigLc8yVp...
- moreover, he may indeed be touching strings occasionally - with or without using the hammers :)
or this https://www.youtube.com/watch?v=PnzQP4M_BQk (Pi) or this https://www.youtube.com/watch?v=a_uL29CKzW8&list=PLpn7yEHjyr... and others (Impressions On Chopin). Not some theory, you can hear the strings bending. Enjoy!
@4d4m: Yes. - and more.. to have such freedom of expression (and some fun, https://www.youtube.com/watch?v=fRj9I5qiiI4 ).
Coming from a synth background I assumed that any timbre variation that pianists can achieve came about via envelope manipulation. That and possibly volume related overtone production I suppose.
I won't be convinced by anything less than a double deaf experiment.
Lol you know within milliseconds how to adjust timbre between key depress speed, sustain pressure, and pedal adjustment to get the timbre you want
Isn't this obvious? Why was this a study? Did you think a hundred years of pianists and piano teachers were just bullshitting you?
To be honest, as a pianist and physicist I’m still sceptical. The only thing you can influence at a mechanical keyboard is the speed with which the hammer hits the strings because by the time contact happens the escapement mechanism has removed the connection between hammer and key. One cannot influence its weight, momentum, angle, etc. So if all there is is a single variable (speed of the hammer), I find it hard to believe that one can change timbre independently on its own.
You are right to be skeptical: the study in question only looked at 'perceived timbre' in the context of pieces performed by pianists. https://www.pnas.org/doi/10.1073/pnas.2425073122
They should have looked at spectrograms at least -_-
In piano performance you often can hear the mechanical sound of the keys themselves as well as the breathing and humming noises from the pianist. Not to mention a performance will be played in an environment where environmental sounds will be correlated with the perception of timber and the pianists physical movements. I don’t see mention if they controlled for all these things.
eg: the Keith Jarrett / David Helfgott recording inversion, performances where you can often hear the notes of the piano over the sounds of the pianist.
But why would you not expect the speed to change the timbre? Lower speed = less force of the hammer hitting the strings = less chaotic excitation of the string during the attack phase = less distortion in the upper harmonics, as well as less sympathetic resonance.
I expect change in timbre, but not independent of intensity and all that changes with a difference in hammer speed.
If all they are saying is that there is a change in timbre tout-court, then it’s trivial. If they’re saying one can change the timbre while keeping the intensity constant, then I have issues.
"Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something."
https://news.ycombinator.com/newsguidelines.html
The purpose of most studies like this is not simply to establish a binary yes or no, but to measure, quantify and explain how something works in more detail than is currently known.
Adding an example to this.
People knew that you would die if you were kept from breathing, but they didn't really know why that was, nor did they know the exact action by which breathing even occurred postulating that it air entered the body through the skin, or perhaps air somehow was necessary to cool the heart which at the time was theorized to be where all thought occurred.
Study as follows: https://pubmed.ncbi.nlm.nih.gov/25532022/
You don't even have to know how to play a piano, just be allowed to touch one, to realise that hitting the keys differently will produce slightly different sounds.
[dead]