Katy Perry donned a glamorous green Yves Saint Laurent gown to step out at the Celebration of Carole King and Her Music event at Dolby Theatre last night in Hollywood. Katy linked up with honoree, Carole, to hit the red carpet for the charitable evening benefiting Paul Newman's The Painted Turtle camp, which provides children suffering from serious illnesses with a Summer camp experience. Also in attendance were Alicia Keys, Jack Nicholson, and Daryl Hannah. Katy and Alicia honored Carole's legacy by performing covers of her greatest hits and teaming up for a duet on stage at the tribute concert. It was a change of pace for Katy, who has herself been an honoree recently. On Sunday, Katy was honored at the Trevor Live annual benefit in LA and she was also awarded Billboard's woman of the year statue last week in NYC.