After ruminating on this further, I've added a few other qualifiers:
1. IIRC, the pianist is vaguely implied to be a reincarnation (either natural or technological) of Beethoven—or at the very least has a particular fascination with his works.
2. I think one of the characters is a red-haired woman? (I appreciate that this doesn't really do much to narrow things down when it comes to speculative fiction.)
3. It was very much a scifi book, not fantasy. Parts are set on a space station, I think.