Singer King Castle and Ozzie Nelson and His Orchestra rehearse for their Federated Broadcasting Company radio show, which has been sponsored for the last three years by Angel Soap. Watching the rehearsal are advertising man Gib Dickson and newspaper columnist Bill Eaton, who has an ongoing feud with King. Meanwhile, singer Kelly Clark arrives in Hollywood from Kansas expecting sudden stardom, as she mistakenly thinks that her friend, Dyalisous "Dynamo" Carson, a tour guide, is an executive at FBC. When her bag is accidentally taken to King by Archie, King's theatrical manager, Kelly meets the radio star. Later, Dynamo gets Kelly a job as a waitress at a nearby hotel, where she once again meets King. King invites Kelly to have a drink, and she ends up singing an impromptu duet with him at a restaurant. The next day, Dynamo asks King to help Kelly get a job on the radio show of disc jockey Joe Smedley. Joe, however, refuses put to Kelly on the air unless King sings with her. King agrees, but only if he can sing anonymously, as he fears being fired from his own radio show for appearing on a rival show. "Kelly and Her Boyfriends" is soon a big hit, and Eaton, who has been plugging the show in his column, tells Peggy, Dynamo's girl friend and Kelly's roommate, that he plans to attend the next show in person. King appears at the show wearing in a fake beard and is introduced to the columnist as "John Smith." Although Eaton suspects King's ruse, he is unable to prove his true identity. Meanwhile, King's ratings on his own show are slipping, and his sponsors, Homer and Clara Hardacre, have notified Gib that they wish to replace King with "Kelly and Her Boyfriends." They offer Dynamo $2,500 a week to sign his clients, so he arranges a meeting between Kelly and the Hardacres at the Orchid Room nightclub. Kelly arrives with King, who soon learns that he is being replaced by his girl friend. Eaton then appears at their table to gloat over King's demise, which leads to a fight between the singer and the columnist. After the mêlée, King is arrested and Kelly is forced to replace him on the air that night. King arrives at the station, however, just in time to join Kelly on the program. After the show, Eaton exposes King's true identity, but agrees to drop charges against the singer for his exclusive story. King and Kelly then announce their engagement, and the Hardacres agree to sponsor a new show starring "Mr. and Mrs. King Castle."
