High school band drummer Jimmy Connors decides to inject some excitement into the Riverwood High School Band by converting it into a swing orchestra. After convincing Mary Holden to join the band as a vocalist, Jimmy asks Mr. Judd, the school principal, to allow the group to perform at the school dance. As the band rehearses for the dance, Mary becomes frustrated that Jimmy is more interested in her vocal abilities than their courtship. At the dance, the band is a hit, and Jimmy decides to enter Paul Whiteman's school band contest in Chicago. To raise their traveling expenses, the band stages a Gay Nineties melodrama for the Elks Club, but afterward they are still short fifty dollars for the trip. Jimmy's troubles multiply when Barbara Frances Morgan, a precocious blonde, enrolls in Riverwood and decides to pursue him. However, Jimmy's interest in Barbara grows when Mr. Morgan hires Paul Whiteman and his band to play at his daughter's birthday party. At the party, Jimmy and his band stage an impromptu performance, which attracts Whiteman's attention. Whiteman offers Jimmy a job playing drums, but Jimmy refuses, remaining loyal to his band. Whiteman then advances Jimmy the fifty dollars they need to go to Chicago, but on the day of their departure, Willie, one of the band members, falls gravely ill from an injury that he suffered during the Elks show and needs an operation in Chicago to save his life. When Jimmy selflessly offers the band's travel money to charter a plane to fly Willie to Chicago, a sympathetic Mr. Morgan sends the band to Chicago aboard one of his company's trains. At the big broadcast, Jimmy and his band are crowned the winners, thus Jimmy's dreams are realized.