Ableton Forum

Basically every Midi Foot Controller can do this for you. Behringer's FCB1010 would be a solution (though a bit expensive, but well worth the money if you need something that should send more than one Signal).

I would basically route every instrument to the channel with the looper. Then you select the Input for the Looping Channel and record a phrase and then switch the input to the next instrument. Thats a very basic idea and i am sure there are better ways to do this. And i am also not sure if there wou...