Where do you go for the ring on Mythology Island?

The ring you need is the Nose Ring from the beastly Minotaur, whose lair is to the left of the Garden of the Sphinx. You will need the reed pipe (Flute) from the Garden of the Muses, which is to the right of Main Street. Play the 8 colored notes in order and the door will open (blue blue green yellow yellow red blue green).

(see related question)