Okay... on the subject of what music everyone listens to... another (maybe more defining thing) question to ask is "what is your character's ideal/dream/situational theme song (like what song comes on when your character walks into a room OR what song defines your character/you (can be either...
i remember when I was a kid, i wrote the author of a book series i read (Encyclopedia Brown) and he actually sent me a letter back with a personal note on the side. it still hangs in a frame in my elementary school library