The Dorsey Brothers were great musicians, and I admire their work greatly, but they weren't actors. They could carry off reasonable performances in cameo roles in films, like Tommy Dorsey did in the film "a star is born" but other than that, they were not worthy of a main role.
However, I am not here to dump this film; it has some fantastic music in it, including a great jam session with Art Tatum. We are treated to a fabulous amount of Dorsey hits like Tommy Dorsey's soulful rendition of "I'm Getting Sentimental over you" and Jimmy Dorsey's swingey rendition of "Tangerine".
Also, there are some enjoyable cameo appearances (apart from Tatum) that include the famous bandleader Paul Whiteman and the singer Bob Eberle.
The worst thing about this film is a romantic relationship that occurs between the DB band's pianist and the singer. This relationship has virtually nothing to do with the film, and amounts to an unbearable schmaltz.
"The fabulous Dorseys" isn't a bad film but you probably have to be a massive fan of the talented brothers to truly like this film. Enjoy the music! 7/10