So let's look at music in fiction. In my stories, it doesn't crop up often (well to date it hasn't anyway) but it could be one of those topics that help you flesh out your created world in your own mind. The more you know your world and your characters, the more convincing you will be when you write about them. So what do your characters like in the way of music? What form does music take in your fictional world? Is it similar to what we have on Earth (classical, pop, rock etc) or is it in a form we don't know?
Is it a question the music doesn't feature in the stories but does help your characters relax so you can refer to it in passing? Can you use the type of music your characters like as a code? My rebellious fairy godmother, Eileen, loves It's My Life by Billy Joel. Her daughter, Jenny, loves It's My Life by Bon Jon Jovi - there's a world of difference between the two songs despite the shared title! My characters' tastes here tell you something about the two characters immediately which, of course, is the idea.
Shakespeare wrote about "music being the food of love". Maybe it should be one source for helping writers develop their characters!