Ain't Misbehavin' is a 1929 stride jazz and early swing tune with lyrics by Andy Razaf and music by Fats Waller and Harry Brooks, written for the Broadway musical Connie's Hot Chocolates. It opened the show and became a hit in Harlem before moving to Broadway, where Louis Armstrong directed the orchestra and delivered a trumpet solo that helped popularize the piece. The original sheet music is in E-flat major. In 1929 the song was recorded by Leo Reisman and Lew Conrad, Louis Armstrong, Bill Robinson, Gene Austin, Ruth Etting, and an instrumental version by Fats Waller. Waller re-recorded it for the 1943 film Stormy Weather, and the tune has since been honored with a Grammy Hall of Fame Award and inclusion in the Library of Congress National Recording Registry. It also inspired the 1978 musical Ain't Misbehavin'. The tune entered the American public domain on January 1, 2025.
