Madonna is interested playing a character made famousish by Lou Reed. Here's the story from sky.com:
...the Queen of Pop has signed up to play Candy Darling, who starred in a series of Andy Warhol's experimental films in the 1960s.She was the inspiration behind the Velvet Underground classic Candy Says and Lou Reed's solo hit Walk On The Wild Side. A source told the paper: "Madonna has been desperate to make a film where she can earn respect for her acting abilities. "She is still trying to shake off the bad publicity from the movie Swept Away. She sees this as her big chance. "She said she would do anything for the part and has agreed to work for free."
Every Advanced musician acts in movies. I think it is because when you are a genius at something (music, for instance) it's just so easy that there is no challenge. That's why you try things that don't come easy, like acting. Madonna couldn't act her way out of a wet paper bag, but I applaud her continuing efforts to convince people that it's the bag's fault.