Inspired by the crooning of radio star Bill Williams, Sylvia Bruce announces to the principal of the Briarcroft School, where she lives and works as a French teacher, that she is going to follow her dreams and quit her job. After abandoning the repressive school, Sylvia tracks Bill to his New York hotel room and confesses to him that his singing changed her life. Bill, who is about to leave the city for Hollywood, slips away from the star-struck Sylvia and heads for Grand Central Station. There, Bill is besieged by reporters, who are anxious to hear about his new movie venture and his romance with French actress and co-star Lili Yvonne. After Bill, Lili, Bert Conroy, the droll director of the film, and Ernest P. Baker, the film's idealistic backer, depart on the westbound train, Sylvia appears on board. Trapping Bill in his rooms, Sylvia confesses her love but is gently rejected by the singer. Determined to stay on board, Sylvia gets a job as Lili's maid, unaware of the actress's relationship with Bill. When Sylvia discovers Bill and Lili embracing, she insults her tempermental employer and is both slapped and fired by her. Once in Hollywood, Sylvia searches for Bill at Ernest's Independent Art Studios and is befriended by Jill Barker, a wisecracking, out-of-work actress. Jill invites Sylvia to room with her and consoles her about Bill. The next day, Sylvia disguises herself in blackface and approaches Bill on the movie set. Although touched by Sylvia's devotion to him, Bill again dismisses her, after which Lili demands that her rival be thrown out of the studio. Aware that Ernest is infatuated with her, Sylvia appeals to him for help, and he generously offers both Sylvia and Jill work on the film. While rehearsing on location, Lili performs badly and is sharply criticized by Conroy. Infuriated, Lili announces that she is quitting and storms away to her dressing room, where Bill is sent to reprimand her. Instead, Bill gives in to Lili's feminine manipulations and forgives her. However, when Lili overhears Sylvia imitating her over the movie sound system, she again denounces and slaps her, and receives a punch in the eye from Sylvia in return. Ernest then declares that Sylvia will replace the puffy-eyed Lili in the film, and the former teacher soon proves to be an overnight sensation. Sylvia's success brings Bill and she together, and after a romantic evening, the two performers pledge their love. When Sylvia makes an unexpected call at Bill's hotel, however, she overhears him singing in Lili's room and angrily snubs him the next day. Hurt by Sylvia's rejection, Bill begins to drink and deserts the film to carouse with Lili in Mexico. Sylvia eventually tracks him to a bar and offers him a chance to return to Hollywood with her. Still under Lili's spell, Bill fails to make the airplane, and Ernest is forced to hire his replacement. As they are filming the picture's big number, however, a sober Bill appears on the set and reunites with an ecstatic Sylvia.