By 1946, African-American casts were making musical films geared for theater distribution nationwide, not just movie houses in African-American communities. In 1947, one independent production company, Herald Pictures, hired Arthur Leonard to direct an hour-long film called Boy! What a Girl!, starring bassist Slam Stewart, drummer Big Sid Catlett, the Brown Dots vocal group and others. The film was shot at New York's Fox Movietone Studio on 10th Ave. and 54th St.
At some point, Gene Krupa dropped by the set to visit friend and drummer Catlett, and Leonard coaxed him into appearing in the movie. The film also featured Tim Moore, a vaudeville comedian who dressed in drag, and it included the song Satchel Mouth Baby performed by pianist Mary Lou Williams and Betti Mays singing Crazy Riffin' by Walter Gil Fuller. Catlett and Krupa solo on Fuller's song. Based on the credits, it looks like all the artists in the film were managed by Billy Shaw, who in the pre-TV age clearly was seeking wider visibility for his clients.
Here's an abreviated version of Boy! What a Girl!...
Here's the complete film with the Mary Lou Williams scene and longer drum solos by Catlett and Krupa...