Maybe I'm missing something here. You do not want to change velocity as a substitute for volume or expression most of the time. It makes the track sound fake or artificial. Most instruments including all stringed ones, all horns and drums change the character of the sound by using velocity. Take a snare drum for example. Hit it soft with a drumstick, then hit it hard. Does it sound the same only louder? Absolutely not. Same with piano. The whole point of paying big bucks for a high end synth for piano is to have multiple velocity layers so as you change the velocity of how hard you play it, the more realistic it sounds. Hit a piano key softly you hear a mellow, round sound. Hit harder and it's harsher and brighter. Synth sounds use velocity to trigger modulation, horns use it to trigger falls, doits, breasth and other variations, it goes on and on.

To me leave the velocity alone and use CC7 or CC11 unless you're using a cheap GM synth. Then it doesn't matter but if you're using a high end softsynth just read the description of the patches and you'll see them talking about velocity layers. It usually works out to the more money you spend the more layers you get.

This is one of those questions that goes to who is asking, what are they trying to do and how sophisticated they are when it comes to this stuff. Many on this forum only use free or very low cost GM synths so using velocity as volume is fine but then the same folks will ask sometime later how to I get more realistic sound? Well, that answer is to spend some money on a better synth which then flows to what I just wrote about velocity. It all goes together, to use a better synth you need to have a better understand of midi or you're not using that synth to it's full potential.

Bob

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