This walkthrough from Mastering.com breaks down Logic Pro's Velocity Processor, a MIDI effect that reshapes note velocities without ever opening the piano roll.
Compress and expand work like a standard compressor, but on velocity values (1 to 127) instead of decibels. Pull the threshold down and dial in ratio to tame an inconsistent performance, then use makeup gain to restore overall level.
Expansion does the opposite, exaggerating the gap between soft and hard hits. That's useful for accentuating a pianist's stronger or weaker hand instead of manually adjusting notes one by one.
Value snaps every note to one fixed velocity, while range compresses everything between a chosen minimum and maximum, producing a softer, more human feel with less obvious programming.