Steamboat Willie
Mickey Mouse serves as a whistling deckhand on a steamboat captained by the villainous Peg-Leg Pete, improvising musical instruments from the animals on board — squeezing a cat's tail to produce organ notes, spinning a goat's tail to play "Turkey in the Straw." The sound was fully synchronized to the picture through a click-track system Walt Disney developed specifically for this production. Mickey's rubber-hose limbs and enormous eyes established the visual template for the friendly cartoon animal that would define the next three decades of character design.
Steamboat Willie was not the first synchronized sound cartoon, but it was the first to achieve wide theatrical release and commercial success with the technique, making it the practical birth of sound animation and the introduction of Mickey Mouse to the world. The character became the most recognizable cultural symbol of the 20th century and the foundation of what would become the world's largest entertainment company.
Disney created Steamboat Willie in 1928, the same year as The Jazz Singer — the first feature-length talkie — as the film industry was scrambling to respond to sound. Disney recognized that cartoons' non-realistic world was better suited to the theatrical exaggeration of sound than live-action drama, and he gambled the company's resources on synchronizing music and effects to the film with precision that live-action productions didn't attempt.
The success of The Jazz Singer in 1927 made synchronized sound an industry imperative within two years. Disney's recognition that cartoons' non-realistic world was ideally suited to musical exaggeration — where characters could spontaneously break into song with full environmental participation — gave animation a unique relationship to music that live-action cinema has never fully matched.