I really wanted this to work for live performance, as I am currently using Logic, and looking for options that can play back tightly synchronized video, and automatically sync to the tempo of the audio tracks, and play synchronized MIDI backing tracks (both notes and controllers), and easily rearrange the set of songs, even minutes before a gig, knowing that tempo sync and lighting will follow.MainStage seems more like a way to play Logic plugins live, along with some additional audio. While there are some hacks for "sending" a MIDI file and using AppleScript to play videos externally, they don't work well. Logic still doesn't even have a method for exporting a MIDI region as a MIDI file with a starting time of 0 / Bar 1, Beat 1, so that also complicates things. Exporting song 15 in my current Logic set has MIDI data starting at bar 2181, with over an hour of silence before any data! So you have to move each region to Bar 1, Beat 1 before exporting. Bummer, I really wanted this to work! And with Apple's existing resources, it seems pretty simple to play back synchronized video, audio, and MIDI from a playlist.