Alicia Keys is adding another note to her acting resume.

The Grammy-winning singer-songwriter has been cast in the big-screen adaptation of the best-selling book, "The Nanny Diaries," Keys' spokeswoman, Kelly Bush, said Thursday.

The film features Scarlett Johansson as a nanny for a wealthy Manhattan family. Paul Giamatti, Laura Linney and Chris Evans also star. Keys will play the nanny's best friend, Bush said.

The character is a far cry from the assassin she plays in the upcoming action flick "Smokin' Aces," which features Ben Affleck, Andy Garcia, Jeremy Piven and Ray Liotta.

Keys, 25, and longtime manager Jeff Robinson formed a production company, Big Pita, Lil' Pita, in January that will create original television and movie projects -- and even more acting opportunities for Keys.