Serenata

From Goodreads:

John Sharp had just flopped in Rigoletto, down in Mexico, when he first saw Juana. Somehow, the beautiful Mexican-Indian prostitute offered him a way back, a chance to rebuild his career in New York and Hollywood. But then, like the snake in the garden, Winston Hawes, the prodigiously accomplished conductor, came back in to Sharp's life and an eternal, and lethal, triangle was formed.