(Prompt 1) I’ve always been really passionate about the music I listen to, and I was wondering if writing about about my identity as a music enthusiast would be viewed as off-topic or would detract from my application? Thanks!
It would not be off-topic, but it also has a high risk of not being interesting either. Lots of people write music and lots of people write college essays about loving music, so you’d really need to work to find a distinctive angle.
The issue is how to make the essay about you.
Thanks @jpheys and @intparent !!! 
Agreeing with the other posters - music is a completely fine topic to write about but try to stand out and show your passion.