Some Houses/Castles have dueling circles, but I don't think you can play different combat music while you are dueling a friend.
I think it would be cool if when you are in building mode in you're house, you can click a dueling circle just as you would a music player, and place music scrolls in it.
You would be able to play different types of themes in the dueling circle too, not only combat themes, such as if it's the yuletide season, you may want to hear a Christmas theme when dueling.
So when you are dueling a friend, you will here different music than the music you would hear outside of the circle, that's if you have a music player playing outside the circle that is.