Logic Studio apps Using expression pedal with MainStage

[Canney]

I am using a Boss Bluetooth expression pedal with MainStage on my MacBook Air. The pedal controls the volume of each track by default. How do I modify my setup such that the pedal controls a different instrument plug-in parameter (say Electric Piano vibrato)?

 

[CSeye]

This may point you in the right direction.

Learn a controller assignment in MainStage

In MainStage, learn controller assignments so channel strip parameters respond to the controls on your MIDI device.

support.apple.com

 

[Canney]

This only seems to apply to parameters available in the patch library. Selecting a "patch" will display the parameters in the workspace. The patch library only contains guitar amp models, it does not contain any of the instruments in the sound library. Can midi instruments, like the Vintage B3, be added to the patch library?

 

[CSeye]

Can midi instruments, like the Vintage B3, be added to the patch library?

Yes.
In the Patch List, select Create New Patch with Channel Strip. Choose Software Instrument. In the Patch Settings/Patch Library, select Instrument...

Your guitar amp and software instrument patches will appear in the patch list. Select a software instrument patch in the patch list. In the Workspace, click on the parameter you want assigned to hardware control. Now click the Assign and Map button. Etc.