In a New York City radio station, band leader Russ Morgan, disc jockey Mike Richards and the station's largest advertiser, Chris Marley, debate a Variety report that radio audiences have declined due to increased television viewership. Marley wants to cut his contract in half because of the article, but Mike argues that radio has created Marley's business. Outside the office, Mike's secretary Marion is asked by her boyfriend Johnny, a talent agent, to help a new client, Vickie Peters, get on the air. Needing to attend to other business, Johnny leaves Vickie with Marion, who is jealous of the talented yet scatterbrained singer. Vickie, oblivious to Marion's anger, expresses her gratitude for the help. Meanwhile, Marley walks out of Mike's office and arrogantly challenges Mike to make a star out of an unknown talent. Marion, having heard Marley's challenge, and softened by a compliment Vickie has paid her, plays Vickie's record. Mike follows Marley into the waiting room and upon hearing the record, decides that Vickie will be the "unknown" he will use to test the strength of his radio audience. Mike then asks Marion to book Vickie for a Saturday night performance at the Rendezvous Club. That Saturday, after Russ and several guest musicians participate in a jam session, disc jockey Gene Norman hands the microphone to Vickie, who sings a beautiful tune. Days later, in Mike's office, Marion accuses Johnny of amorous advances toward Vickie, but Johnny argues that with Vickie's success, he will raise enough money for him and Marion to get married. Meanwhile, at the Association of the American Disc Jockeys conference, a group of prominent disc jockeys decide to prove their audience's loyalty by supporting Mike's "unknown," whom they all agree is talented. Once the disc jockeys return to their respective stations and play the tune, Vickie's record sales soar and the newspapers run stories that Marley's challenge was a failure. Later at the station, Russ and Mike discover that all the musicians who played on Vickie's album had exclusive contacts with other recording studios, thus her record must be pulled from circulation. Mike then sends Johnny out to research the possibilities of a new recording contract for Vickie and assigns Marion to write advertising copy for Vickie to read on his show. Some time later, when Johnny invites Marion out for dinner, she assumes he is going to set a wedding date, but Johnny just wants to celebrate that fact that Vickie's success has raised a lot of money for his and Marion's future. Marion retorts that they do not need the money and should marry immediately. Frustrated by Marion's insistence, Johnny suggests that if they feel so differently about the subject, they should end the relationship. The next day Johnny visits Marion and insists that his relationship with Vickie is purely professional, but Marion pays no attention. When Johnny threatens to date Vickie, Marion, furious that her marriage plans are ruined, decides to get even by writing insulting advertising copy about Marley Candies. When Vickie unwittingly reads the copy on the air, all of the radio station's personnel run to the booth to stop her. Mike and Marley smash through the door and start attacking Vickie and Marion, who can only defend themselves by breaking records over the men's heads. Scheduled to go on the air at that very moment, Foy Willing and the Riders of the Purple Sage sing a tune while the ruckus continues in the background. Later, Marion drinks with Vickie and her friend, talent agent Happy, to forget the horrible day and the loss of her job. Happy, determined to get his client H. J. Ball on the air, asks for Marion's advice about influencing Mike. Marion suggests that Happy "polish Mike's medals" by complimenting him on his horticulture hobby. The next day, Happy employs the technique with success and H. J. is scheduled to sing for the Disc Jockey benefit. Meanwhile, when Marley receives reports that his business is booming despite the insults, his confidence in radio advertising is restored. At the benefit, Vickie and Marion show up together and wait off stage with H. J. and Happy while Russ and his band play. After Russ, H. J. is called onstage; during his song Marion and Johnny reconcile, and Marley forgives Mike for Vickie's false advertising.