The first Unreal also used multiple tunes within the same module. I've even managed to get one working under jj2 (accidentally). Download and install my RHG pack. Go to the very first castle level and listen to the calm music. Then kill yourself (jjk) and see how the music changes after you die. I've always wondered why this happens, but never got to explore it. Also, you must not be using my music autochange patch or you won't hear the change.