I experienced a strange issue in the simulator: after exiting to the home screen from the "Level 1-1" game ("Menu button" then selecting "home"), the music playback is stopped as expected, then I pressed "Menu button" again, and one more time to exit the menu, and the game's music continued playing, while I was on the home screen. It continues playing until I start an other game or the Settings.
I do not have a device yet, so I don't know if this is only a simulator issue or not.