I think that a balanace between silence and music fits. I imagine like minecraft does it, would be a way that could suit your game too. just the silence itself builds such great tension, but a track every now and then would be very nice to have to listen to at occasions. though however you go about doing it, I'll always and honestly love the game mechanics as they're amazing!
ah alrighty then. I guess I could also check on both the sites in case you have done something different with the other one. just to be sure ^^