Jonathan makes a good point. The way one sense supports and enhances another is really interesting, and we tend to be very visually oriented. I also find the phenomenon of synesthesia fascinating. There are people who see colors when they hear music… different colors are actually associated with specific pitches. Some composers (Skryabin, Rimsky-Korsakov) associated keys with colors. Olivier Messiaen  was very influenced by his own synesthesia, wrote extensively on color and music, and even indicated colors in some of his scores as an aid to interpretation.

-Sharan