Paramount had their own in-house animation studio, Famous Studio (later Paramount Cartoon Studio), for years. Even then, however, they had no qualms about releasing animated shorts from other studios, such as the George Pal Puppetoons, Hal Seeger's Muggy Doo, few from John Hubley, and the various shorts directed by Gene Deitch. In fact, they released an entire series of shorts from Deitch called Nudnik.
Deitch recalls making Nudnik with fondness and remarked that they were his favorite cartoons to do. The pilot, Nudnik #2, was nominated for the Academy Award, which may have spurred Paramount Pictures into picking it up.
Paramount released the Oscar nominated short as Here's Nudnik. One big difference in this short than with the rest in the series is the music. According to Deitch Paramount requested that they don't use the blues music (done by SH Quintet, a Czech band) so they opted for the ragtime-ish tune done by Stephen Konichek, who did music for various Deitch shorts including his Tom and Jerry.
Here's the cartoon in question. Note that my copy was very out of sync but I managed to get it fixed before I uploaded it.