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Realistic touch... in what way? There is no standard for touch in the acoustic pianos and grand pianos.

In a similar fashion - realistic sound... in what way? There is no standard for sound in the acoustic pianos and grand pianos.

What I look for in an acoustic is the mechanics of the keyboard and the quality of the sound, as well as the connection between keyboard and sound. Having all that in mind, all but the most expensive new uprights are garbage. The only upright I was content with playing on at the Musikmesse Frankfurt was the top-model Petroff (€16k - the price of a small new car).

It all depends on the budget and purpose. If you are a beginner-to-intermediate player then even a lowly-end Yamaha P-125 would do. If you want more bells and whistles you climb up the ladder very quickly. If you want a nice looking cabinet you get an Arius or a Clavinova.

However, if you are at pro level then it becomes more difficult. At that level, the digital pianos are good for the technical work, for expressiveness a pro always begs for an acoustic. It is not possible to replicate the expressiveness of a real piano with the 128 grades of initial touch response the MIDi offers. A high-end player uses touchè, soubtle touch, which cannot be reproduced by the digitals.

To summarise, the digitals are good for the mass market. Get any of them and don’t bother with the marketing material. None of them comes close to an acoustic and none of them will ever do unless they switch to 16 bits MIDI (allowing for 65000 grades of intial touch) and super extra long samples. However, this will come at a price only a selected few will be willing to pay.

If 128 grades are not enough, then how many are required?
You seem to say that 65,000 is enough ... but isn't that too much?Who can control 65,000 levels of touch? Or even 1,000? Or even 128?

The current MIDI standard uses 8-bit messages for most of its functionality, the highest-end bit is mostly a +/- switch. That means we are restricted to 128 levels of initial velocity, 0 beiing silence (produces no sound). That is far from enough for expressive playing at professional level. On the other hand, the mechanics of the digital keyboard does not allow it - you see, there is a very wide variety of keyboards. If we talked Yamaha (I am not aquainted with the other brands) there are GH, GHS, GH3, GH3 wood, GrandTouch and whatnot. Apart from the marketing blabla, all of these keyboards are restricted by the MIDI standard.

Now, to your question, how many levels of initial touch are enough - I cannot answer. A survey among the professional pianists should be conducted. I am a computer programmer and am long past my best days as a pianist. However, if we take into account the CD recordings (44.1kHz, 16 bit) it seems that 16-bit values for velocity is enough for a digital recording. Of course, there are purists with excellent ears who can hear even more than that.

With practice you can surely train your hands to produce more than 127 levels of initial force when playing from ppp to FFF, especially if you have a good acoustic instrument.

Not according to Dr. John Mortensen (start @ 7:28):


(BTW, read Dr. Mortensen's discussion in the comments with "fjloma" on why other factors are not practical/relevant.)

I didn’t manage to play a single note multiple times within a -1/+1 velocity range, then I suppose a 127 levels resolution is enough for me.

I find that I need at least 1000000 levels of velocity to truly express myself while playing piano. I say skip the 16-bit MIDI and go directly to 32-bits or even 64-bits (Sarcasm)

I have played jazz privately and professionally for fifty years. Thirty years spent on a Steinway B. I now have a Kawai MP11se. I can honestly say that while a great acoustic is something much more, I am perfectly satisfied with the expressiveness of the Kawai. Until I, as a player, surpass the capabilities of a particular instrument then it works for me,

It is not okay for a beginner to play on any keyboard as Troll suggests. He or she should get the best instrument possible acoustic or digital. And all this super velocity level stuff is irrelevant. A real player can coax a great sound out of the poorest instrument (within reason). Snobbish judgements do not help people who just want to have a decent and fun playing experience.

An acoustic piano might have 50 dB of dynamic range. If we have 128 velocity levels then each level could be 50/128 dB = 0.39 dB above/below that of its neighbor.

Hearing tests show that few people can hear a change of even 1.0 dB, though some claim to hear 0.5 dB. So 0.39 dB grading is finer than what a person can hear.

Increasing the number of levels from 128 to 65,000 is beyond pointless. It's just silly.

Also, I don't know what leads you to this:
As for this ...I don't see the relevance. The 16-bit resolution of an audio recording has nothing whatever to do with the velocity layers of a piano.

And and I don't know how you could possibly substantiate this:

Martha Argerich is known to have pounded more than 65,000 levels out of her Steinway! (I’m not yelling; the exclamation is used for emphasis)!

There is some misconception here with application of 8/16 bits math. Velocity layers are applied for extracting different harmonics, not only for the dynamic range. Sampling a good grand using 127 layers may reveal a very rich timbre palette of the instrument. Today only the most advanced plugins are close to this level of detail.

Furthermore, some harmonics may appear only in very specific velocities, depending on the physics of the instrument. So, even quantifying velocities using 127 levels may be insufficient. I think, however, that for most practical purposes 127 is enough.

I believe he is wrong.

How was this measured?

Using 65,000+ microphones, of course!

I don’t think there are tiny range of velocity which triggers some harmonics. The higher the velocity, the faster the hammer bounce back from the string and the louder high harmonics are triggered. With lower velocities, the hammer spend more times at the strings and a mellower sound is produced. The actual transition depends of the softness of the hammer.

Ferruccio Busoni was famous for being able to produce a MIDI value of 128 out of his Casio Privia.

His Privia went up to 129.

Those keyboards are restricted by their sensor timing resolution, not be the number of steps MIDI can map.

The sensor timing resolution defines

1. the lower limit of velocity they can detect (maximum time)
2. the upper limit of velocity they can detect (zero time)

The practical resolution inbetween is usually lower than 100 steps and there is noise/variation in key speed detection due how mechanical/rubberdome contacts work. Digital pianos need a lot of sensors (264), so not every model can have the most precise optical ones.

MIDI is NOT what limits digital pianos. The usual actions themselves do not fully utilize standard MIDI resolution.


16 bit PCM sampling has nothing to do with MIDI at all.

I'm not sure if you are being serious or making a joke, but if the former, you left off the emoticon.

Not by a human being, with earholes. Quite an important factor, in the argument (I say).

I think he picked that number because MIDI control options are 8 bit (128 values) or 16 bit (65,535 values), there is no way to choose anything in between. So as soon as you suggest that something needs more than 128 values, you're up at 65,000. If you just want 256 values, MIDI is such that you still have to implement something capable of 65,000 values.



Control doesn't matter. Even on a 128 value keyboard, you may find that any attempt to repeat a value could easily be off by 5 in one direction or the other. But if you were to say that value 5 could as easily be anything from 1 to 10, and 15 could as easily be anything from 11 to 20, and so on, you could end up concluding that you only need about a dozen velocity values. But really, even with +/- 5 variations, that doesn't mean you wouldn't notice the difference if, instead of 127 values, there were only a dozen. Repeatability of a particular value is irrelevant. The smoothness of a crescendo does not depend at all on your ability to repeat a specific value in the middle. And a scattering of notes at plus-or-minus 5 centered around 63 can still be sonically different from scattering of notes at plus-or-minus 5 centered around 63, or 64, or 65, etc.


Personally, I think 128 values is probably plenty, but that video strikes me as poor and unconvincing. At that 7:28 part, why should we believe that nobody could possibly produce a sound level, for example, between his level 1 and his level 2? Or that he might not get a slightly different volume for level 2 if he did the same thing again? Or that, if he did a gradual ppp->FFF crescendo, that each of his strikes would be exactly one of the 7 volumes he created?


While 65k may be silly (and as I said, is only referenced because it is the next MIDI increment about 128), and while I agree tha 128 is probably enough, I don't think your math actually proves the point. Maybe nobody can hear a volume difference of less than .5 dB if the two sounds are otherwise identical, but as Andrew_G points out, when you change velocity on a piano, you change not only the volume, but also the timbre (the relative volume of various harmonics), and I believe you also change the envelope (the amplitude curve from the initial strike), so the two sounds are no longer otherwise identical. Once you make other changes to the sound besides just volume, a smaller level difference can become more noticeable. For an extreme example to illustrate the point, there's no doubt you can hear the difference between a C and a C# even if played at the exact same volume, because another attribute of the sound has changed, in this case the pitch. Since multiple attributes of a sound can change when hitting the same note at different velocities, you can't use volume alone as an indicator of how small a decibel difference we may be able to perceive. After all, if the pitch is changed, we can notice a decibel difference of zero!

Another point that might be worth consideration is that the sensors measure our finger's force linearly, while the decibel scale is logarithmic, so these things do not have a 1:1 relationship. Related to that, even using your example of 50 dB spread over 128 values yielding .39 dB of difference between each value and the next, programming it like that would not necessarily produce a sonic output anything like how you would want it to play.