Level select:
Press Start at the logo and wait for Wayne and Garth to begin singing. Press X + L + R, Up + Y +B. Press Select to change the level number that appears at the bottom of the screen. An alternate method is to press X, Y, B, L, R, Down, Up at the title screen.
No music:
Press Start to pause game play. Press Start on controller two. Game play will resume without the music. Repeat this code to enable the music.