Setting Up All MIDI Inputs
When you record MIDI, you can specify which MIDI input each recording MIDI track should use. However, you can also record any MIDI data from any MIDI input. You can specify which inputs are included when you select All MIDI Inputs for a MIDI track.
Procedure
Result
When you select All MIDI Inputs on the Input Routing menu of a MIDI track in the Inspector, the MIDI track uses all MIDI inputs that you specified in the MIDI Port Setup.