This scene from "A Clockwork Orange" is pretty disturbing. I didn't watch the entire rape, the web videos stop when he starts to cut her shirt. I get the idea though. Obviously in the original version, he's joyously in love with the girl.
I think in this scene, he's obviously a twisted guy and is mentally confused. It's not weird that he would sing that song, as his character probably doesn't have much culture to him, and might have only remembered that song at the moment. Also, the juxtaposition of violence and rape alongside a song like "Singing in the Rain" is interesting. The viewer is confused because they want to feel happy and think positive when they hear that song, but the action of rape and destruction of life and morality shatter those initial feelings and the viewer is left feeling torn. The actor does a great job at making the viewers think he is crazy. Singing so easily makes it look like what he is doing is effortless, when really it could be just an avenue his character is taking to relieve pain from a bad experience he had.
