Send each MIDI channel to its own instrument. The router takes one MIDI input and gives you sixteen MIDI outputs: each of the sixteen input channels picks an output, or Off to mute it.
What it is for
A sequencer or a MIDI file often carries several parts on different channels: drums on one, bass on another, chords on a third. Put the router in a rack after the source, then connect each output to the instrument that should play that part. The notes keep their original channel as they pass through.
Changing routes while you play
Notes that are already held keep going to the output they started on until they are released, so remapping in the middle of a phrase never leaves a note stuck. The next notes you play follow the new mapping.
