Another great piece of software I've been using for the same composition mentioned in my previous post, is the Gestural Music Sequencer.

This little gem will take a video feed, live or pre-recorded, and generate MIDI information based on the brightest point of the image. It's very simple to use, requiring only the IAC bus to activated to route it to your DAW of choice for gestural MIDI goodness.

Scales, keys, note, note value and rest probabilities can all be programmed, and my results so far have been very musical.

One small hiccup I experience when using pre-recorded material, is that the resolution must be 640x480 for the bright point to be tracked accurately.