Greetings and salutations,
Just want to add a few thoughts to the conversation. First of all, while I am a visual artist, I opt for seeing music is not the same as visual art. The areas of the brain that apply to visual modalities would not apply across the board to all art. In addition, I think we lose something of real value if we work with the assumption that visual art covers the territory, or that visual art is somehow primary.
My point here is that a musician does not "use" his mental imagery the same as a visual artist, or as a sculptor. Musicians think in notes, sounds, music structures, etc. Sculptors think in regards to touch, texture, and the like. etc. The photographer thinks in regards of control of image shape, sharpness, perspective, and depth of field, etc. The inherent training for each of these art discipline force one to entrain and condition one's mind accordingly. I have met musicians that could not notice any shade of a particular color on a photograph, let alone a difference in luminocity. However, will notice a note played by a piccolo in a symphony orchestra, while the opposite for a photographer will be the case. He might love music, but might not be able to make sense of the harmonic or contrapuntal structure of the piece.
We train our mind to respond accordingly to our interest and I should say focal interest. We attend to what gives us the best aesthetic "pleasure" and experience, ignoring and even denigrating other things
Many similarities between composing music and composing "art" could be inferred -Rhythm, Repetition, Unity, Mood, Movement, Use of Positive/Negative Space, etc... The creative process.
p.s. I play hand drums and guitar … music stimulates the creative process …