Using a Force Touch trackpad with your Mac, you can perform some GarageBand functions by force-clicking or tapping with three fingers. The trackpad also has haptic feedback built-in that, when Force Touch is turned on, lets you feel a light vibration when you drag a Volume slider to the 0 dB position or a Pan knob to the center position.
In GarageBand General settings, select the Enable Force Touch trackpad checkbox.
See General settings.
In macOS System Settings > Trackpad > Point & Click, turn on “Force click and haptic feedback,” then click the “Look up & data detectors” pop-up menu and choose an option:
Force Click with One Finger: Press firmly on the trackpad until you feel a deeper click.
Tap with Three Fingers: Use three fingers to tap the trackpad.
In the Tracks area of GarageBand on Mac, force click an empty area in a software instrument track.
In the Tracks area of GarageBand on Mac, force click an empty area in a Drummer track.
In the Tracks area of GarageBand on Mac, force click an empty area in an audio track, then choose an audio file from the menu that appears.
In the Piano Roll Editor or Score Editor of GarageBand on Mac, force click an empty part of the editing area.
In the Piano Roll Editor or Score Editor of GarageBand on Mac, force click a note.
In the Tracks area of GarageBand on Mac, force click the empty area below the last (lowest) track header.
In the Tracks area of GarageBand on Mac, force click the automation curve of a region.