You Don't Know What You're Doin'!

You Don't Know What You're Doin'! is a 1931 animated short subject directed by Rudy Ising and produced by Leon Schlesinger as part of the Merrie Melodies series from the Harman-Ising studios and distributed by Warner Brothers. First released on October 21, 1931, the film is perhaps one of the most amusing and effective of the cartoons from the studio's earliest years.

The story involves the character Piggy, who picks up his girlfriend and takes her to a theater where a hot jazz orchestra is playing. Piggy mocks the trumpet soloist, and plays a corny chorus of the 1873 hit "Silver Threads Among the Gold" on the saxophone. The audience, led by three drunk dogs in the balcony, then mock Piggy with the title song "You Don't Know What You're Doin'". Piggy is then joined onstage by one of the drunk dogs (a black dog, perhaps a prototype of Goopy Geer). Piggy picks up their bottle of bootleg hootch (the film was made during alcohol Prohibition in the USA), takes a swig, and starts having hallucinations; he pours some booze into the radiator of his automobile, which arches its back like a frightened cat and takes Piggy for a wild ride through the city.

The musical soundtrack was done by the then-nationally famous Abe Lyman Orchestra (though on some prints mis-attributed to the Gus Arnheim band), which adds a happy energy throughout the cartoon. The eccentric virtuoso trombone playing of Orlando "Slim" Martin is prominently featured. Martin played not only music but also some rather bizarre effects on his horn (the techniques he used to produce some of his sounds continue to puzzle other trombonists). His trombone solo representing the drunken automobile is especially memorable. The Schlesinger Studio had their sound effects department construct mechanical devices to roughly reproduce some of Martin's sounds, which became standard cartoon sound effects.