One day when practicing a phrase, I noticed a particular note sounded “harsh”. Then it got me puzzled. I am using a digital piano (with Pianoteq). How can a single note be made sound harsh if the sound engine is generating that sound solely based on key velocity?

This reminds me of another comment I received when a few forum members pointed out, helpfully and rightfully, that in a certain passage I sounded like I was pounding the keys more than before and the result is not as pleasant. I did hear the same unpleasant result. But I also had an explanation - that passage was marked forte, and my supposedly “pounding” in fact is true to that dynamic (and verifiable by the velocity curve).

But the real question that has since baffled me is: how can a digital piano make an “ugly” sound just by playing forte. Unlike an acoustic piano, a single note, played in forte, on a digital piano would sound the same every time it is played exactly in that dynamic. Put it in a different way, why would digital piano sound engineers record or model keep any particular sound that’s always “harsh” or “ugly”? They wouldn’t if they could have that sound always “beautiful”, right?

Then it dawned on me: the “harshness” is not from the note itself, but its relations with the notes that’s surrounding it. It just sounded “out of place”. I experimented, and found out not only can I tame the harshness by playing that note softer, but I can also achieve the same by playing the notes before and after louder.

    After a lot of reading, watching, and thinking on this topic of piano tone quality, I am going out on a limb and say: I believe this is the same with acoustic pianos.

    Now, most of you know I am a beginner beginner. I also have never laid hands on an acoustic piano. So am I totally clueless and ignorant making a claim like that? Well, bear with me. I was born in a family of engineers, trained in natural science, and worked with technology. So there is a part of my brain for logics that always must be reconciled with what I perceive. In my experience, more often than not, art and science agree. Only when science is based on incomplete information or understanding do they falter. Acoustic piano actions, based on widely available information online, does not appear to have much mystery on how it works. So the science should be able to explain it well.

    As far as I understand, the double escapement causes the hammer to be out of the players control in its final travel to hit the strings. The hammer also travels in a single direction, which means it will always make contact with the string in a single way (assuming no pedal is depressed). Therefore, aside from tuning and regulation changes (hammer hardness, friction, etc), the only variable at the time of playing is velocity. As long as the velocity at which the hammer leaves escapement (or hit the string) is the same, it will produce exactly the same sound and the same tonal quality.

    I have watched and read many teachings on play in beautiful tone, what to do or not to do: hit the key straight down, or with an angle, or with finger only, or with arm weight, or push the key, or pull the key, or tip of the finger, or with the fleshy finger pad, or land from high above the keys, or lay finger on the key surface before pressing, etc. I am not doubting these things don’t make any difference. On the contrary, I firmly believe they do. Yet, the disconnect that bothers me is the reasoning behind. Few of those teaching explains why they work, leaving it more to vague concepts as more often in artistry.

    That is until I realized the tonal quality, although being solely based on velocity, can be perceived quite differently because of its surrounding notes. Then it makes sense that bad tonal quality actually comes from imprecise control of the dynamics (velocity) of the notes that are interacting. Therefore, all those ways of varying the body’s interaction with the keys is just a quest of achieve ever more precise control of the key velocity.

    I have come across a few piano teachers elucidating exactly this concept. Aleksander Woronicki in one of his articles clearly stated velocity is the only target a pianist controls. Shijun Wang in one of his videos said the same - but he added on more dimension which is a perfect illustration of what I mentioned how science falters with incomplete understanding (on my part). Dr. Wang said the second aspect a pianist can control the tone quality is the depth of playing the keys. I realized this can be explained if one considers the involvement of the damper. When the key is played very close of the surface, the damper is not lift as high, and at softer/slower velocity, the damper could even come back into contact with the string by the time the hammer meet the string, affecting to tonal quality.

    I hope some of you find this topic interesting. I am eager to hear what you think. And I'd especially welcome those would share their knowledge and/or experience that can help broaden my undertanding.

    I also want to make clear I am in no way trying to discredit any piano techniques and teaching. On the contrary, I feel this discussion can help clarify that there are various paths to the same goal, and may also shed light on why some path suite one player more than another because we all are made slightly differently.

    This is an interesting observation - at first I thought maybe the velocity map for that one key might be off. But I will have to experiment with that on my Yamaha P515.

    If you have never had a chance to play an acoustic grand, I would suggest you seek one out someplace and try it. The tonal palette you can achieve on an acoustic will blow your mind. And while digital pianos will always sound the same, acoustic pianos have temperaments that change with the weather and can even sound a bit different from day to day with the swelling and shrinking of the soundboard and other wooden parts. I am always amazed at how much more you can get out of an acoustic piano, tone-wise.

      danno858 acoustic pianos have temperaments that change with the weather and can even sound a bit different from day to day with the swelling and shrinking of the soundboard and other wooden parts.

      Great point. This is something I can comprehend and agree with. Even though I have yet to experience this with piano, I can relate that old wood furnitures and houses are like living things. So for a piano, the weather would be like the nature's tuner. I also have no doubt that pianists adapts to this and the great ones makes the best out of this wonderful characteristic.

      On the other hand, when writing my original post, I was more thinking about a piano's tone at a given moment. Like one often see in some classes a teacher demonstrates how to play a note or a chord using different body gestures. And I do believe the resulting variation in tone quality is happening and true and effective. I am just contemplating that some of the explanation of why the method worked may not align with what really happened. I now think the tone quality changed because the key velocity produced changed, and the variation in gesture really serves to help the player to better control the key velocity.

      I don't remember where I heard this saying - it says the pianist is an illusionist. Maybe tone quality is one of those magic illusions.

        However it happens, the acoustic seems to have an almost infinite amount of tonal breadth - I believe the pianist has so much more control over the process in an acoustic - I have also heard the only thing we can control is the velocity of the hammer but there is so much more that goes into the tone production as Ithaca has mentioned, the quality of the hammer, the type of felt used, how the hammer is shaped, the strings etc. - I can get so much more variety of tone from an acoustic - and I have much better control of say, playing the left hand part much quieter than the right hand part (if needed). I have limited control of this on my P515. I always wondered about which DP or midi controller would have a better action so I can see if it's just limited to my P515. I am curious to try Iternabe's test on my P515 when I get home tonight.

        This has been debated endlessly at PW and other places. Many pianists (even very good ones) are adamant that there is a difference in tone quality independently of the velocity of the key but physics says that is simply not the case. While you can use body movements to help you make the sound you want the explanations given by many pianists amount to basically voodoo.

        iternabe the “harshness” is not from the note itself, but its relations with the notes that’s surrounding it.

        Yes, it's all contextual. For another example, "legato" is not only about continuity of sound but about continuity of the musical line. You can play completely detached and without pedal and it can still sound more legato than if you play with the pedal down but without good phrasing.

            Ithaca I think (totally not sure) that you control the hammer velocity and the damper behavior via the impulse that you apply at the keys.

            I agree. This is also something I have been pondering over. I think I can reconcile the impulse and the velocity.

            When I said velocity, I am think the velocity of the hammer at the moment it leaves the escapement. From then on, it is out of the pianist's control. This velocity is the result of the impulse from the finger, or more accurately from the whole playing apparatus (finger, knuckles, wrist, arm, shoulder, back).

            To understand the impulse, I'd like to think its polar opposite. Think an example of an extremely heavy moving object collide with an extremely very light stationary object - the light object will accelerate almost instantly to the heavy object's velocity. Make that analogy with a heavy arm, falling at a controlled constant velocity from high above the keys, and striking with steely fingers - that will move the key instantly to match the fingers velocity. That would be super accurate control of the velocity at the with the hammer strikes. Only that we humans, or most of us, cannot do it that way. The key need to gradually accelerate from stationary to a certain velocity at the let-off point. This is the impulse. And this gradual acceleration can also vary a lot based on how we perform the impulse, and even where we start the impulse from. Although the goal is to control the velocity at let-off, I doubt any human is capable of sensing speed at that precise moment. We have to control the velocity at let-off indirectly by controlling how we execute the impulse. So the real question, again, is what kind of motion gives us the best control of the impulse and the resulting hammer velocity.

              Just to clarify, there are many things that go into tone production and a good pianist can certainly control it to an extent using the pedals. I often use partial pedaling or add a touch of una corda as additional effects that I control mostly by ear but that is not the main point of contention. The controversial point is only whether there exists a separate dimension of "harsh" independent of volume for a single isolated note and physics says there isn't. Harshness is an illusion of playing something out of place in the musical context.

              Ithaca
              I don't get your point about impulse. Impulse is just the time rate of change of momentum and since the system is contant mass it means it's the rate of change of the acceleration. In the end it all translates to velocity.

              Ithaca For this kind of problem I would want good empirical data.

              You would have to do it with a machine of some kind because there is no way a human can control precisely how much acceleration a key has.

              I am not denying that different gestures help you control the sound. There are many subtleties of your body movements that can help shape the resulting sound in relation to everything else you hear. What I'm saying is just that all of that sound shaping is a contextual illusion not the result of some undefined tonal quality of single notes.

                  BartK While you can use body movements to help you make the sound you want the explanations given by many pianists amount to basically voodoo.

                  If the method works, who cares if the explanation is voodoo, right? 😉

                  Well, I was thinking what if a method work on many but fails on a few. It is then that having voodoo explanation can be of little help. Because if the reason of why something works is incorrect, it may lead one to keep trying ineffective solution. Having the explanation align with the underlying physics will have a much better chance of finding the right solution.

                    Ithaca I think people who say “physics says” aren’t modeling the mechanics accurately enough. An idealized model will likely fail to explain/predict some real-world behaviors.

                    I am in agreement with you here. Almost all models are approximation. We like to start simple, and think that it's not necessary to include things that don't affect the result meaningfully or perceptibly. But a critical part of scientific training is as soon as models (theory) and reality (experimental results) deviate, more rigorous investigation is warranted, and minds/models/theory should be ready to be changed.

                    Good luck obtaining grants for this kind of research on piano sound, though! 🙄

                        iternabe I am in agreement with you here. Almost all models are approximation. We like to start simple, and think that it's not necessary to include things that don't affect the result meaningfully or perceptibly. But a critical part of scientific training is as soon as models (theory) and reality (experimental results) deviate, more rigorous investigation is warranted, and minds/models/theory should be ready to be changed.

                        Yeah, OK, but if you want to propose a different model you have to at least present an argument of why the simple model fails and a tentative explanation. I'm not getting what exactly it is about impulse that changes the way the hammer hits the string. Some people have proposed that the elasticity of the hammer stores some angular momentum but I'm very sceptical that this effect is non-negligible compared to the total momentum of the hammer. I'm too lazy to do actual calculations but I'm open to arguments (with math) if you think you can convince me otherwise.

                          iternabe Good luck obtaining grants for this kind of research on piano sound, though! 🙄

                          That might be a good challenge for the science Youtubers. I don't know if you watched it but a few years ago there was a wager between Steve Mould and ElectroBOOM where each attempted to give an explanation of the Mould effect when dropping a chain of beads from a height. There were a lot of experiments and back and forth arguments and other Youtubers like Veritassium also put in their 2 cents. It was very entertaining to watch. Maybe someone is up for a piano tone challenge. 😄

                            A lot of comments about the beautiful, rich and expansive tonal color palette of acoustic piano are making me longing for one! Weather, tuning and regulation, and just the analog and infinite grades of motion of the piano action is just fascinating. Though, some of these factors are affecting the tonal quality over time, or after mechanical adjustment.

                            I was contemplating more along the line of what a pianist can do with their interaction with the keys at a particular moment to affect the tonal quality.

                            In my opinion it’s more about controlling the hammer better up to the point of no return. Since that’s all we can really do. I found an interesting university study that seems to touch on this discussion. It’s lengthy and I just started reading it:

                            https://public.websites.umich.edu/~brentg/Publications/Thesis/Chapter2.pdf

                              danno858 that's interesting. It seems to explain @iternabe's observation with human perception:

                              By carefully governing the timing overlap of notes as they follow one another, the musician can evoke a certain percept in listeners which will not be labeled in terms of timing at all; it will be labeled by the ear and auditory perceptual centers in terms of the frequency domain, that is, timbre. Although it is not, in physical terms, independent control of timbre and intensity, it is perceived (and labeled) as such.

                              I was going to suggest it might be an auditory illusion. That article seems to go to similar direction. But it also suggest that the pianist have some control over the perception. I will read the rest of it now 🙂

                              Human brain is complicated. I suspect brains of different individuals process the same auditory input differently. Not only that, the input data is different too. Because our "hardware" is different. We all have different physical ears. Some people even have different left & right ear canals/structures.

                                iternabe careful now. You will start hearing weirdness in pianoteq which will ruin it for you 🙂

                                    hebele iternabe careful now. You will start hearing weirdness in pianoteq which will ruin it for you 🙂

                                    Hey, maybe that will be the day I run out of excuse not to buy a 7-foot grand! 😜

                                      danno858 I found an interesting university study that seems to touch on this discussion. It’s lengthy and I just started reading it:

                                      https://public.websites.umich.edu/brentg/Publications/Thesis/Chapter2.pdf

                                      @danno858 I cannot thank you enough for find this chapter, as it is truly enlightening. I have yet to read the second half of the chapter on synthesizer. This paragraph has already made me want to get the entire book.