Setting a reverse controller can be really helpful in MainStage, especially if you’re using faders to control B3 organs. Here’s how to do it: 

1. Open MainStage. Select a template.

2. Click on a controller. I’m going to select the Treble function for this demo. 

3. In the Screen Control Inspector window at the bottom of the project, select “Treble”.  

4. Select “Invert Parameter”.

5. Your control will now function in the opposite direction from now on.