Poly aftertouch events in Logic Pro for Mac
Polyphonic (poly) aftertouch events are generated by mechanical pressure sensors beneath each individual key on some MIDI keyboards. The resulting sound modulation affects only the particular note that is pressed harder (after the initial keystrike). Only a few keyboards offer this capability. You can create poly aftertouch events and other types of MIDI events in the Event List. For more information, see Create events in the Logic Pro Event List.
Poly aftertouch event parameters
Ch(annel): MIDI channel of an event from 1 to 16.
Num(ber): Displays the MIDI note name (C3, G4, and so on).
Val(ue): Displays the amount of pressure on the key (0 to 127).
Note: The format of displayed poly aftertouch values can be changed in the Display MIDI Data As pop-up menu. See General View settings.