I'd say it would have something to do with the images in the music. The colour of the notes. When I hear Coltrane I image landscapes, both interior and exterior. The interior landscape of the artist competing with the impressions of the world around him/her. I know its touch-feely but when I was writing my own essays on American poets I got hooked on Lee Remicks reading of Emily Dickenson's I heard a fly buzz when i died...The slow lazy southern drawl of the words is (italics) the music and the feeling behind the words. anyone can read words in their head it is not the same as hearing them rendered within the context of the time and situation of the writer.