Hello Larry,
There was a really good website explaining everything you needed to know about MIDI and Disklavier. Unfortunately, a few years back, it was suddenly gone.
Anyway, your standard MIDI file has velocity from 0 to 127. Playing a software piano, 0 already lets you hear a note. 127 is the loudest it was sampled or processed.
If you hit a key very softly, your Disklavier will not make a sound until you hit a key hard enough, so that the hammer touches the strings. On the other end, you may be able to get a 127 from your Disklavier, but you have to hit the key so hard that you won’t feel good about it.
Those are the extremes, but your Disklavier is able to reproduce those notes.
This is the reason why it’s never a good idea to let your Disklavier play a normal MIDI file. A loud rock piano is often played between 100 and 127. Some MIDI files use 100 or 127 the whole time and just turn down the volume to get a hard sound. If you let your Disklavier play that, I could imagine that you might even damage it.
On the other hand, if you just turn velocity down by 30 or so, soft notes may not even yield a sound.
That means you have to compress the MIDI notes. Logic Pro can do that, and I guess there is a lot of software out there that can, too.
Also, remember that the volume buttons on your Disklavier are not volume knobs since that is not possible. Instead, if you turn down the volume, the velocity is reduced, or, I guess, compressed as well, because otherwise, a really quiet passage won’t make a sound at all if you turn the volume all the way down.
Also, if you play „normal“ MIDI files, you will find that the Disklavier will often not play a repeated note because the Disklavier, as a real piano, will need time to move the hammer back. If a repeated note in the MIDI file was set to legato, the Disklavier can’t play the second note because the hammer is still at the strings. There is a MIDI setting within the Disklavier that will create the needed spaces, but you will get latency, and the overall velocity is slightly different.
Cheers,
Guido