Silly Symphony is a series of 75 animated short films produced by Walt Disney Productions from 1929 to 1939. As their name implies, the Silly Symphonies were originally intended as whimsical accompaniments to pieces of music. As such, the films usually had independent continuity and did not feature continuing characters, unlike the Mickey Mouse shorts produced by Disney at the same time. (Exceptions to this include Three Little Pigs, The Tortoise and the Hare, and Three Orphan Kittens which all had sequels.) The series is notable for its innovation with Technicolor and the multiplane motion picture camera, as well as its introduction of the character Donald Duck in 1934.