Katy Perry

A former Christian artist, Katy Perry rebranded herself as a larger-than-life pop star and rose to prominence in 2008, when she topped the pop charts with "I Kissed a Girl." After several years in the industry -- a period that included a Christian album, shelved collaborations with the Matrix, and an unreleased solo project -- Perry had suddenly become one of the biggest pop stars, celebrated as much for her outsized behavior and outrageous fashion choices as her music. She managed to top One of the Boys (2008), her platinum-selling pop debut, with Teenage Dream (2010), a follow-up that spawned five number one U.S. pop hits, including "Firework." Prism (2013), her third album for Capitol, was highlighted by "Roar" and "Dark Horse." ~ Andrew Leahey