John Howard Sharp is an American opera singer down on his luck, having just bombed in Rigoletto in Mexico City when he first encounters the beautiful Mexican-Indian prostitute called Juana. Serenade is the story of the eternal triangle - with a difference. Miraculously, she offers him the chance to rebuild his career in Hollywood and New York but then Winston Hawes, the young, rich and well-connected conductor who had first launched Sharp, comes back into his life with terrible consequences.