Maybe someone else will have a better method, but I feel like you could do this with the bitsymuse hack by having a set room background track and then calling a long sound track as a sound effect. I'm not sure if it would support multiple sounds being layered with the hack as is, but if you played around with it, it seems like it should be possible?
It's a cool idea, I hope you are able to find a way to make it work!







