Nice thread.

Besides some of the books already mentioned, I have enjoyed Modesitt's The Soprano Sorceress and The Spellsong War. A sequel, Darksong Rising is theoretically in the works.

Teen fiction with a musical backdrop that I have enjoyed: a novel called Midnight Hour Encores. I have forgotten the author. The protagonist is a cello player.

Okiemockbird (a.k.a. T in Oklahoma)