You're the One (1941)

In this 100% fictional film, in which not a single performer plays "Himself" nor "Herself" but the two lead performers use their own name as a character, a singer named Bonnie Baker (Bonnie Baker, with a strip-tease singing voice auditions for a job singing with orchestra of Luke Laramie (Albert Dekker)), but his taste runs to blondes and Bonnie, at the moment is a brunette. Meanwhile, Luke goes to the weight-reducing sanitarium run by Dr. Calonna (Jerry Colonna), hoping to lose some weight in order to get a spot on a radio program sponsored by the maker of a non-fattening food product. Dyeing her hair from brunette to blonde, Bonnie, a fictional character played by a singer with the same name, and her agent, "Death Valley Joe" Frink (Edward Everett Horton), follow Luke to the screwy sanitarium, run like a nightclub and a summer resort by Colonna and his lovely nurse, Miss Jones (Lillian Cornell), who primarily sings and dances. It soon gets broad when Aunt Emma (Renie Riano) shows up and turns out to be Faro Fanny, Frinks' old sweetheart from his Death Vally days.