Just curious, do you mean velocity level (itself), or are you talking about the actual velocity curve programed within the voice to trigger what's called velocity switching? Maybe I'm reading your post wrong. Velocity curves are when you strike the key harder and the sound (not just the voume) change. Good example is a 60's electric piano sound. It gets more dirty and distorted when you stike the key harder. When that sound is triggered it's referred to as a Velocity Switch.
Squeak
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