You know how XBox can put music from your CD's onto the game, well I found out how you can do it with a GameCube.
First, you need all of these.

-1 Nintendo GameCube
-1 DVD Player
-1 TV w/AV slots (not a TV/DVD combo)
-Your favorite music CD

This is what you do:
Hook up the DVD Player (Audio only) to the AV Slots. Then, Put in your CD into the DVD. Set your track you want to listen to. Put in ONLY the Video AV jak from the gamecube to the TV. Then play your Game. Although you don't here the game sounds, you can listen to your songs while you play. Try playing music based on the game your playing. Example: "Ghost Busters Theme" while playing "Luigi's Mansion".