A combination of a radio quiz show in and around the record-spinning radio program, "Make Believe Ballroom", created by Martin Block and Al Jarvis. Liza Lee (Ruth Warrick), fast-talking press agent for Al Jarvis (Al Jarvis), persuades Jarvis to stage a Musical Mystery Contest, with a $5000 prize to the person who can first name the most musical numbers and their performers. Drive-in carhops Gene Thomas (Jerome Courtland) and Josie Marlow (Virginia Welles) run neck-and-neck in the contest, They are friendly rivals until college professor Leslie Todd (Ron Randell) begins courting Josie. Gene is thrown out of the contest on the grounds he tried to bribe sound engineer Jerskin Elliott (Louis Jean Heydt) into telling him the name and performer of the final, deciding mystery tune. Believing that Gene is innocent, Josie tricks a confession out of Elliott and clears Gene for the grand finale.
Gene and Josie tie and share the prize money and together buy the drive-in of Gene's dreams. Liza and Leslie also decide to form a life partnership.
Filled with one dizzy shot after another of spinning 78 rpm records that fade into a singer or band doing their stuff. Their stuff includes Frankie Laine (On the Sunny Side of the Street), Kay Starr (Lonesomest Gal in Town), Jack Smith (The Way the Twig is Bent), The King Cole Trio (The Trouble With Me is You), and pre-teen Toni Harper on three songs (Candy Store Blues, Little Miss In-Between and, with The Sportsmen, Hamburger Heaven.) The combined bands/orchestras of Charlie Barnet, Jimmy Dorsey, Jan Garber, Pee Wee Hunt, Gene Krupa and Ray McKinley work together on "Joshua Fit the Battle of Jericho," in addition to band-alone renditions of many songs.
Adele Jergens (then being groomed for bigger things by Columbia) drops in as a decorative guest star on the radio program. The plot itself plays out in about 25 minutes of the 79-minute running time, and the rest of the film is all music.