I think there would be different levels of "music" like simple patterns of tones, then melodies, polyphony, symphony, etc. Various schools of magic as many as there are musical traditions and scales or the equivalent in each tradition. Perhaps even culture develops to match with this new type of "music" as a type of ritual performance, like sacred dances and ritual musical dramas.

There is a series called the Book of the Stars I believe, they had an interesting magic system. The constellations of the world formed letters which formed an alphabet, and you spell words with them. There were alternative forms of magic too where one weaves together many syllables into a long droning recitation or something, I forget exactly. But that is kind of what I'm envisioning with the "levels" building upon each other