Synesthesia or Chromaesthesia
I have had several people that have played in our band describe this condition of seeing color with music called synesthesia or chromaesthesia. I personally tend to imagine or visualize light and dark, form and movement. I've often thought of my primitive and abstract sculptures as having musical patterns of light and dark. Themes and variations. It comes down to smaller things as well Viola = dark, Trumpet = bright and every shade in-between. I also think of music in terms of emotive intensity of ease and unease. Hope that's not to weird. Relative pitch also can make me feel at ease as opposed to the uncomfortable feeling I get when something is not in pitch relatively. I should also say that melodic lines seem to have emotive qualities of dramatic speech. I hear or imagine the emotive preverbal intent of a melodic idea or phrase. Some Jazz forms have expletives and soft quiet melodies like a lullaby say soothing things for example. I guess I could go on and on about this subject. Some melodic patterns set to meter seem to scream for someone to dance to it. Even to imply the type of movement that should be done to it. Setting ones feet and body in motion to the divisions suggested by rhythm. Did I mention Guided Imagery, which is sometimes used in therapeutic settings. Much of the sound of Poetry read out loud has qualities of music in its cadences and meter. Sadly I've talked to people who can not even imagine what one is talking about when you say a Viola sounds dark. (a good kind of dark) The benefits and associations of music seem to be many and of great variety. I've only scratched the surface of an amazing subject.