Edit note velocity in the Piano Roll Editor
Each note in the Piano Roll Editor displays a horizontal line. The length of the line relative to the overall length of the note shows the note’s velocity. Velocity indicates how hard the key was struck when the note was played, which usually corresponds to the note’s loudness (the MIDI velocity range is from 0–127, with 127 being the loudest). Velocity can also control other synthesizer parameters, such as filter resonance or cutoff, alone or in conjunction with volume level.
You can also display velocity using different colors, by choosing View > Set Note Color > By Velocity from the Piano Roll Editor menu bar. When this command is chosen, higher velocity notes appear in warmer colors, and lower velocity notes appear in cooler colors.
Color coding makes it easy to see the velocity of individual notes, and to see the overall range of velocities in a MIDI region. As you change the velocity of the notes, their color changes in real time.
For more information about color assignments in the Piano Roll Editor, see Change the color of notes in the Piano Roll Editor.
Edit the velocity of notes
Do one of the following:
Select one or more notes, then drag the Velocity slider in the Piano Roll Editor header left or right.
Drag over a note vertically with the Velocity tool.
A help tag showing the note velocity updates as you drag. The line inside the note also updates to show the velocity change.
If the MIDI Out button in the Piano Roll Editor menu bar is active, the note sounds as you drag.
When you edit the velocity of multiple notes, the relative differences in their velocity values are retained. If the velocity value of any of the selected notes reaches the minimum or maximum value (0 or 127), none of the notes can be adjusted further.
You can override this behavior by holding down Option while dragging. This allows you to continue altering the velocity values until the selected note reaches the minimum or maximum value. By overriding, the velocity relationship of this note to the other notes is altered.
Assign the same velocity value to selected notes
Hold down Option-Shift while dragging one of the notes with the Velocity tool.