Apple Soundtrack Pro 3 - Manual (Page 408)

Recording Control Surface Automation
Once you have connected a control surface and mapped the controls you plan to use,
you can use the control surface to control volume, pan, and other functions in your
Soundtrack Pro projects. Using the automation modes described in
Automation Modes ,
you can record control surface movements while a project plays.
To record control surface movements, follow the procedures described in Recording
Automation Data .
You can thin automation data recorded from a control surface. For information on thinning
automation data, see
Thinning Envelope Points in Recorded Automation Data .
408 Chapter 18 Using Control Surfaces with Soundtrack Pro