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This pop star, the daughter of evangelical Christian pastors from the Santa Barbara area of California, is known for hits such as 'I Kissed A Girl' and 'Firework,' as well as her ever-changing and often wacky looks. She is married to British comedian Russell Brand and once spurred controversy by showing cleavage in a 'Sesame Street' music video.
(Pictured: Katy Perry and Barbara Walters are shown in this photo as part of the special, 'Barbara Walters Presents: The 10 Most Fascinating People of 2011.')
(ABCNews Photo / Donna Svennevik)