What do you do when you like the music you like but your girlfriend doesn't, and she doesn't want to hear it at all but you love the music and can't stop listening to it?

Well really, it's music. Have a talk with her, a relationship is a compromise, you should he free to listen to whatever type of music you want and the same for her. If a relationship is too "one sided" it's not going to last long, or if it does, feelings will be hurt and in the end its not worth all that over music......js