Hold Select and alternately press Left and Right repeatedly until 'Sound 01' appears.

Code - Effect

At the title screen, hold Select and press Run until the phrase 'Area 1' appears. - 30 Continues

Enable the Sound Test cheat. Press I, II, Select 22 times. Then hold Select and Run until the game starts. - Area 0, 30 continues

Hold Select and alternately press Left and Right repeatedly until 'Sound 01' appears. - Sound Test

Hold Right, and keep pressing Run quickly at the title screen. - View Ending