I talked to a rock band a while back and they were using an VST plugin that converts audio signals to MIDI (i can't remember the name though). They used a multi input sound card in Ableton, created some tracks and for each member of the band and let the VST plugins route MIDI to Resolume. This way the guitars and drums were triggering effects and clips in Resolume. It sounded like a difficult setup but they were having a lot of fun using it.
Then again, sometimes it's easier to just put a fader on your foot and do it manually (like I do here)... the whole FFT analysis sending MIDI data is kinda wonky.