In most of his movie vehicles, bandleader Kay Kyser played a bandleader named Kay Kyser. In Swing Fever, however, Kyser is cast as aspiring songwriter Lowell Blackford. Though he isn't too successful at peddling his songs, Blackford does have one unique talent: The ability to hypnotize boxer Killer Kennedy (Nat Pendleton) into winning fights. Blackford is coerced into using his "whammy" on Kennedy by Ginger Gray (Marilyn Maxwell). On the night of the championship bout, Blackford finds out he's being used, but goes through with his hypnosis to save Ginger from gangsters. The whole thing ends rather incongruously with a patriotic floor show, a specialty of MGM films of the period. Several guest performers lift Swing Fever out of the ordinary, including Lena Horne and the Merrill Abbott Dancers. Also appearing is an uncredited Ava Gardner as a sarcastic receptionist.