What is the best way to represent audio visually? (x-post from UX)
What a human (or their ear-brain) perceives in sound is a psychoacoustic phenomena, and may or may not be exactly related to the actual audio as recorded.  e.g. the exact notes, beats and instruments that a human "hears" may be influenced by visual cues, memory of other similar music, and the musical context around the actual sound of the note in question.