This week, I watched a kind of unusual musical: Love Me or Leave Me (1955). It wasn't unusual in form or content, or in who it starred; it was a biopic of 20s jazz singer Ruth Etting and her gangster husband Marty Snyder, and it had lots of songs and dance numbers, all of the entertainer-doing-a-show-for-an-audience variety. It starred Doris Day and James Cagney.
Wait a minute -- Doris Day was a singer, James Cagney played gangsters a lot -- what's so unusual?
How about the fact that Doris Day played a pretty unsympathetic character? That strike you as unusual? She was manipulative, she was greedy for fame, she pouted and threw tantrums. Not the Nice Girl Next Door that she usually played.
As for James Cagney, while he played a crook and a jerk and a self-serving jackal, he actually ended up getting more of my sympathy than Doris Day. Because for all his faults, Marty Snyder really did fall for Ruth Etting, and she used him to get famous and then divorced him. There were a couple scenes where Cagney nearly had me misty-eyed.
Of course, it's a fictionalized account of their lives, so who knows what they were really like. But that's how they struck me in the movie.