Assuming you’d use the OT as the clock master, you connect its MIDI OUT to the IN on the RYTM, the THRU of the RYTM to the IN on the A4, and the THRU on the A4 to the IN on the Voyager. This is called “daisy-chaining” for obvious readons. You’ll sequence the Voyager with the OT’s MIDI tracks and you can connect the OUT on the Voyager to the IN on the OT if you like.