Mickey Mouse’s first words were spoken not by Walt Disney but by Carl Stalling, who went on to compose 22 years’ worth of soundtracks for Warner Bros’ Looney Tunes and Merrie Melodies cartoons.

I have written before about interactions between the two titans of 20th century Western animation: Disney and Warner Bros (specifically Mel Blanc’s Pinocchio). The links go pretty deep, and Carl W. Stalling has roots in both.
Stalling began his career playing the organ accompaniment for silent movies. Walt Disney hired him in 1928 as his music director. Stalling was a natural, and developed a technique that synced up music and animation with unprecedented precision – as seen in the early Disney short The Skeleton Dance.
That short, by the way, is a Hallowe’en staple in my household – check it out here:
In his role as Disney music director Carl Stalling was the very first person to provide Mickey Mouse’s voice, in the short The Karnival Kid. While Mickey had appeared in a few short films prior to this 1929 one, his earlier appearances had been mute or accompanied only by laughing or crying.
The first words Mickey Mouse spoke? “Hot dogs, hot dogs!” This would later serve as the inspiration for the Mickey Mouse Clubhouse song “Hot Dog” (written and performed by They Might Be Giants). Funnily enough, Walt Disney does provide a voice on The Karnival Kid: that of Minnie Mouse.
Anyway, Stalling left Disney in 1930 and began work on the Warner Bros series Looney Tunes and Merrie Melodies, the cartoon shorts that would introduce Bugs Bunny, Daffy Duck, and Porky Pig to the world. Stalling was incredibly prolific: over the next twenty-two years he apparently composed every score for Warner Bros’ animated shorts. Perhaps six hundred of them in total, including classics such as Rabbit of Seville and Rhapsody Rabbit.
His extraordinarily rapid composition technique was simple: he had a host of go-to musical cues that he would return to over and over. Some of those became famous in their own right… but that’s a post for another time.