Okay, playing the http://microgue.blogspot.com/ build, it seems like the music starts a new loop every time you get the gem?  Like, after you bring the gem to the king and go back down the staircase, the music starts playing again in parallel with the current music.  So if you win three times in a row it gets very discordant.

Is the version of MicRogue linked in JasonPickering's signature (http://forums.tigsource.com/index.php?topic=23617.0 ) not the current build?  I've been playing that, but it doesn't seem to match the things they were saying on Roguelike Radio, and looking at it that thread doesn't seem to have been updated since February.  I only found this thread today, but the opening post doesn't have a link to any builds.