Serenade tells the story of poor vineyard worker Damon Vincenti (Mario Lanza), who becomes an operatic tenor, and is involved with two women — one a high society hostess, Kendall Hale (Joan Fontaine), the other a Mexican bullfighter's daughter, Juana Montes (Sara Montiel).

Juana Montes is a Mexican prostitute who sees Sharp as gay and therefore a trouble-free partner to open a brothel with.

The two lovers come into conflict with the local police and flee to Los Angeles, where Sharp reestablishes his singing career, more successful than ever.

But once they move to New York, the singer must struggle against the renewed blandishments of the gay impresario, whom Juana eventually murders with a torero's sword.

"[3] Mann was admonished not to make a film with Lanza, due to the tenor's notorious reputation for being temperamental and very difficult to work with.

"[3] Reviewing the film in The New York Times, A. H. Weiler wrote that Lanza, "who was never in better voice, makes this a full and sometimes impressive musical entertainment.