Corrected entry: When first talking to the Happy Mask Salesman, the room is completely empty. After retrieving the Ocarina and returning to the Salesman, he is now sitting in front of a huge organ.
Trivia: When meeting the Happy Mask Salesman for the first time, he is carrying a lot of masks on his back. One of the masks is Mario's face.
Correction: There is enough time between the events for him to have moved the piano there.
Knever