Oso is given a training mission from Professor Bufo to open a garage by pressing buttons on a keypad in a certain pattern. Oso presses all the buttons at once and gets launched into the air. That's when he gets a special alert. A boy named Henry is having trouble playing "Old MacDonald" on the piano while his grandpa is taking a nap. Oso must help Henry learn how to play the right notes before his Aunt Stephanie comes over so he can play for her.