
If each of these was on a separate MIDI channel:
-Channel mute mode where MIDI notes turn channels on and off
-Voice switch mode selects a different voice.
-Pattern switch mode where you can use MIDI notes to change where you are in the time line.
-Step record and skip MIDI commands.
PS. The chord mode is really cool, but it took me using MIDI input to figure that you can select multiple notes to enter at once.