They are not comparable. RS-422 is a specification at the physical/electrical layer. MIDI is a protocol at the logical layer. You can transmit MIDI over RS-4

They are not comparable. RS-422 is a specification at the physical/electrical layer. MIDI is a protocol at the logical layer. You can transmit MIDI over RS-422. However you cannot transmit RS-422 over MIDI. That makes no logical sense. Like saying you could transmit a chicken sandwich over HTTP.