DJ’s regularly use cross faders to adjust the volume of two sound sources simultaneously (i.e. fade out one track while fading in another track). There are several really useful ways to use a crossfader as a keyboardist- probably my favorite is adjusting the volume balance between two channel strips (a piano and a pad, for instance). Here’s how to do it: 

1. Open MainStage. Select a template.

2. Go to the Layout mode by using command-1. 

3. Drag in a horizontal fader. 

4. Go back to the Edit mode using command-2. 

5. Add a second channel strip using the plus button on the RH side of the channel strip window and select a preset.

6. Click on the horizontal fader, then clickthe Assign and Map button. 

7. Click on the channel strip’s volume button.

8. Click on the + button in the Screen Control Inspector, and then repeat step 6 with the volume fader on channel strip 2. 

9. Click on “Invert Parameter Range” on the 2nd mapping.

Assign the onscreen fader to a midi controller, and you’re good to go. 

Need help with MainStage? I offer one-on-one online training here.