Instructions
Determine the correct tune to play based on the area of the game you're in. If you're trying to enter the Minotaur's maze, look at the front of the closed door to see the correct tune, which is displayed as a pattern of flower petals. If you're trying to put Cerberus to sleep, open your "Items" bag again and check the color-coded tune on the "Pipe Tune" card.
Open your "Items" bag and locate the Reed Pipe card. Click "Use" on the card and the flute will appear at the center of the screen.
Click the color-edged holes on the flute -- blue, green, yellow and red -- in sequence to match the tune needed.