A mysterious thief has stolen the prosperous Happy Valley's most prized possession: the musical Singing Harp. Can Mickey, Donald, and Goofy find the answer in the irritable Willie the Giant's magnificent castle up in the blue sky?
Walt Disney
as Mickey Mouse (voice)
Clarence Nash
as Donald Duck (voice)
Pinto Colvig
as Goofy (voice)
Sterling Holloway
as Narrator (voice)
Paul Frees
as Ludwig Von Drake (voice) (uncredited)
Billy Gilbert
as Willie the Giant (voice) (uncredited)
Anita Gordon
as Singing Harp (voice) (uncredited)
