Begin by entering the Sound Test code - however, press Right, not Down, at the end of the cheat. Time will increase much, much faster.
At the title screen, on controller 2, hold A and keep holding. Hold B, then release B, then hold B again. Release A, then hold A again. Release B, then hold B again. Release A, then hold Right. Finally, release both Right and B. Now you can press the directional pad on controller 2 to hear the music or sound effects.