I loved "Songmaster" by Orson Scott Card. It's sci-fantasy. The last part, about the former "songbird" as an old man will live forever in mind.

Kim Stanley Robinson wrote The Memory of Whiteness. Science-fiction. Mathematical music is the theme. Not as fun, but quite interesting.

A note for people interested in DeLint. He had nine? unpublished novels when he got Moonheart published. Most of the unpublished novels then got published. Some are crap. Choose carefully.