Why Cameron Diaz Won't Sing in Public

By Steve Helling

12/15/2008 at 10:30 AM EST

Don't expect Cameron Diaz to break into song in front of the footlights anytime soon.

The actress, who will reprise her role as Princess Fiona in the fourth animated Shrek film in 2010, has ruled out joining the musical version of the cult tale on Broadway.

"What they do up there ... is, to me, impossible," Diaz told the Associated Press at Sunday night's opening of Shrek The Musical at the Broadway Theatre – where the crowd included America Ferrera, Rosie Perez, Ben Stiller, Kathie Lee Gifford, Hoda Kotb, Phylicia Rashad and Joan Rivers.

And though she isn't compelled to hop on stage and join the cast, Diaz, 36, says she's a fan of the live show, which received generally warm reviews.

"It's hilarious," she said. "There's so many laughs. It's great to see all the actors playing it together, because when we do it for the animated [movies], we never see each other. We don't work together."

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