The large Play button is the All Play button. When pressed, all active Parts inside RMX that have Grooves loaded will begin playing.
If Play was initiated with the All Play button, then pressing the button again a second time will also stop all parts.
If playback was initiated by a Part Play button, then pressing the All Play button will activate Play on any remaining active Part that isn’t currently playing.
The Stop button is the All Stop button. Pressing this button while any RMX parts are playing will stop all playback.
NOTE: The Play/Stop buttons do not synchronize with your host’s transport unless the Host Sync Button is enabled.