Walt Disney enlisted former colleagues Hugh Harman and Rudy Ising to help create this underwater Silly Symphony. Ocean waves form merbabies who are summoned to an aquatic circus playground on the sea floor, where they interact with a parade of seahorses, starfish and other marine life, before disappearing into the surface from which they came.
Score
Orchestra committed harder than most Oscar nominees.

Director
Rudolf Ising
Trivia, insights & behind the scenes
Disney 'borrowed' Harman and Ising from Warner Bros. for this one-off collab like a messy custody arrangement.
This 1938 short arrived right before Disney pivoted to features, making it a fossil of pure pre-war whimsy.