Start/stop midi during audio clip playback?

[TerryTester]

My setup is this: Ableton Live controlled via MPD32 + an MPC2000XL connected as midi slave to Live, so when I launch a scene (consisting of audio clips) in Live, the MPC starts playing a selected sequence - which is cool.

However, it seems the only way to stop the MPC is to hit the space bar, which also stops everything else that's playing in Live. Is there a way to kill/relaunch midi during playback without stopping the audio clips from playing?

Thanks!