Well, you need to make sure ‘transport receive’ is active on your Rytm. But I guess if I’m understanding you correctly, you probably know that and want to set up a trigger somewhere in the middle of your Ableton track. I can’t think of a way to do that. Not so convenient, but I guess you could create a song on your Rytm and just have a blank track until you want it to start up. Maybe someone more familiar with Ableton will have a better suggestion.
mmm, can’t think of anything that could help apart from something like Max4Live or similar. a MIDI filter of some sort which could i.e.: turn a note played in the MIDI clip into a start/stop message. i don’t think you can setup a MIDI clip to do such a thing in Live
Why don’t you just automate a mute on the AR track? Just strategically place your project on the timeline so that it lands at the right time for your AR