To activate a Sound in a Multigrid track via MIDI program changes:
- Click the Grid layout button
- Ctrl+Click on the track name (above the radio buttons with the Sound names)
- Map that control to MIDI>0-based Program Change (the program number corresponds to the slot number of the activated Sound)
- Ctrl+Click again to select the MIDI channel for that control
To send MIDI continuous controllers and note events on a specific channel to a specific Sound in the Multigrid, edit that Sound and add a MIDIVoice as the rightmost Sound in the signal flow. Then you can set its channel and polyphony of the MIDIVoice.
Hope that helps. Thanks from a sunny (today) Champaign!