
Intro to the Piano Roll Editor in GarageBand on Mac
The Piano Roll Editor shows the notes in a MIDI region as colored bars in a time grid. Horizontal lines show the time position, while vertical lines indicate pitch. A keyboard along the left edge of the Piano Roll Editor provides a reference for the pitches of notes. The Piano Roll inspector, to the left of the notes area, includes controls for editing MIDI regions and notes.

When one or more regions are selected, the Region button is highlighted and the following controls appear in the Piano Roll Editor inspector:
Region Name field: Edit the name of the selected regions.
Time Quantize pop-up menu (with Strength slider): Quantize the timing of notes in the selected regions.
Transpose slider: Change the pitch of notes in the selected regions.
When individual notes in a region are selected, the Notes button is highlighted and the following controls appear in the Piano Roll Editor inspector:
Insert pop-up menu: Choose the note value for notes to insert.
Time Quantize pop-up menu: Quantize the timing of selected notes.
Velocity slider: Change the velocity value of selected notes.