MainStage Define the source for program change messages
By default, MainStage receives and responds to program change messages from all connected MIDI controllers. Some MIDI controllers, however, send program change messages while performing other operations. You can define the source for program change messages for a concert, so the concert responds to messages for only one MIDI device, port, or channel.
Choose the source for program change messages
In the Concert Inspector, click the MIDI tab, then choose the source device or port for program change messages from the Device pop-up menu.
If you want to limit messages to a single MIDI channel on the device, choose the MIDI channel from the Channel pop-up menu.