The Fabulous Dorseys

The Fabulous Dorseys is a 1947 fictionalized biographical film which tells the story of Tommy and Jimmy Dorsey, from their boyhood in Shenandoah, Pennsylvania through their rise, their breakup, and their personal reunion. The film was also released under the alternate title "The Fighting Dorseys".
Background.
The film is a musical comedy based on the lives and careers of Tommy and Jimmy Dorsey. The Dorsey Brothers star as themselves. Other actors include Janet Blair, William Lundigan, Sara Allgood and Arthur Shields. Janet Blair demonstrates that she is a highly competent singer.
The "side plot" focuses on a romance between Jane, who grew up with the Dorseys and becomes the singer with their band (Janet Blair demonstrates that she is a highly competent vocalist), and Bob Burton, who leaves his employment as a support pianist for the cinema and joins the Dorseys. Bob writes music and strives to complete an original American-sound concerto. 
There are also cameo appearances by other jazz musicians of the period: Paul Whiteman, Charlie Barnet, Henry Busse, Bob Eberly, Helen O'Connell and Art Tatum. Pianist Tatum "is shown playing in a night club with the piano surrounded by the Dorsey brothers and other well-known musicians, who finally join him in an ensemble blues."
The Jimmy Dorsey composition and theme song "Contrasts" is played in the movie. "Green Eyes", "Tangerine", "I'll Never Smile Again", "Marie", and "I'm Getting Sentimental Over You" are also featured in the movie, along with "To Me" and "Dorsey Concerto". Paul Whiteman and the Orchestra perform "At Sundown". Art Tatum performs "Turquoise" and "Art's Blues" at the piano.
The film was written by Art Arthur, Richard English and Curtis Kenyon. It was directed by Alfred E. Green.