Not sure how well this could be done but I know in different private servers I used to play in like 10 years ago. You could talk to an npc or do a command and within that room you could set the background music to whatever you wanted. Would be nice to be able to just chill and listen to some of my favourite background music.
I think they are going to implement this in the Lounge with the music box NPC which doesn't do anything right now. Probably soontm.