Malvina Adams, an antiquated school marm, teaches music appreciation to the bored pupils of Newton High, who prefer "swing" to Chopin. When Mr. Stevens, the school principal, suggests that she is out of step with her students, Malvina decides to write a song for the school band. The students reject the song, "Fight on for Newton High," as too corny, however, and Malvina's niece Abby mails it to a music publisher in New York City, where band leader Bob Crosby buys it for his band as a novelty number. Bob likes the song so much that he seeks out its composer to write more choruses. Surprised to discover that the writer is an elderly woman, Bob offers Malvina a job singing her own song. Abby dismisses Bob's idea as improper, but Malvina longs for the excitement of New York and accepts his offer. Malvina's debut is a big success, and she hits the nightclub circuit. Soon the novelty wears thin, however, and her popularity wanes. Meanwhile, Abby's animosity toward Bob has turned to love. After Malvina's contract is canceled, she tries a comeback by penning another tune, inspired by Central Park, but her attempts meet with failure until Bob secretly rewrites the composition. The song becomes another hit and Malvina, content with her success, returns as a celebrity to her music class, while Bob and Abby journey to California for their honeymoon.