The Band Concert (1935)

Continuity mistake: When we see Mickey Mouse's band at the start of the cartoon, look at the stand where Mickey is and you can see there is a small brown box with nothing around it. But when the camera pans in on the band in the next shot, there is now a piece of paper next to the box and on the box as well.

Trivia: "The Band Concert" was the first Mickey Mouse cartoon made in colour.