Rihanna was a "natural" in Battleship.

The pop singer makes her movie debut in the forthcoming summer blockbuster alongside Taylor Kitsch and Brooklyn Decker; director Peter Berg was delighted with her performance.

"She was great. She has a very strong part. I was surprised no one had ever thought to hire Rihanna. I was a huge fan of her videos. Obviously she's sexy, but she had this real intensity. I'm like, 'Someone's going to get her.'"

Peter was most impressed by Rihanna's attitude and willingness to learn when they first met to discuss the movie: "When I met with her, she came in a T-shirt and jeans, no makeup, very natural. She was like, 'Look, I want to be an actress. Don't kiss my ass. Don't lie to me. Push me. Treat me as you would any other actor. Help make me good.' She is really, really good in Battleship."

The filmmaker also admitted he is a fan of seeing singers and musicians making the transition to acting.

"I've always believed in musicians as actors. I had great success with Tim McGraw in Friday Night Lights and The Kingdom. Musicians have been acting since Frank Sinatra won an Oscar for From Here to Eternity. Barbra Streisand, Kris Kristofferson, the late Whitney Houston, I thought, was tremendous in The Bodyguard. As recently as Mariah Carey in Precious, she was great."