Graphical sound visualization (as available in several music players, eg winamp) is mostly used for fun, to add some visuals to the music, related to it in some way ( pseudo spectrum analysers, frequency vu meters, oscilloscopes, spectrograms, etc). But they do not provide a musically meaningful representation, they do not give enough cues -say- to "see" a major chord as different from a minor chord. I'm interested in this kind of sound visualization, such that the colours/shapes attempts to mirror/reveal the basic musical properties. Some desireable features:
It should have pure audio as input, not notes (not midi)
Uniform pitch change (chromatic transposition) should result in esentially equivalent visuals (apart from some trivial global change: translation, rotation, zoom...)
Intervals and chords types should be (up to a point, perhaps with some training) visually recognizable.
It could exploit sound dynamics (i.e., each visual frame not necessarily depends only on the current audio frame), but should be lightweight enough to be implemented in real time.
Does anybody know about some work (academic, commercial, whatever) along this lines? I've seen this, but it does not seem to lead very far...
(I have not the reputation to create an appropiate tag, perhaps "synesthesia"?)