The hills are alive with the sound of reader Josh's musical discovery (unless you already knew about it) concerning old Xbox games:
Because of the "Music volume level persists between game / reboots" fix in the Spring Dashboard update, I found out purely by accident that you can now listen to music while playing XBOX 1 games on the XBOX 360.
Just start up any ol' playlist or a ripped CD and fire up Halo 2 or any other XBOX 1 game that suits your fancy. While the controls won't be there when you hit the guide button, you can still control the action with your 360 remote (if you have one).
Who wouldn't enjoy playing Halo 2 with "Climb Every Mountain" playing in the background?