I think the OP means to be able to change the music file that plays in specific situations. So if you were to enter Haukke Manor the game would recognize to play Haukke Manor theme (which is awesome), but as soon as you are engaged in battle the game sets priority to battle music to play until out of combat.
This game also needs the "/battlebgm on/off" command so I can quest/explore while listening to the zone music and never losing the mood because I aggro or have to complete a 30s fight for the quest.