The single player version would do your job perfectly. Use one of the inputs to trigger the start and use another to trigger a second file - this stops the first one straight away and starts the second one (which is just a file name but no music) so it effectively stops playing.

I could probably build a much cut down version for your application as it would save a lot of connectors, 1 x vol pot, 2 x opto chips etc etc???

Price - always a problem - not sure yet.....

I have been looking for something like this for a while, but need a simpler version to basically start a song on start button and to finish at end of game.
I am asking you if it can be triggered to shut off the looping song at the end of a game?
Nice work 
Do you have a BALL PARK $ as yet?