Katy Perry is one of the most interesting pop stars of the past decade. Emerging from the wreckage of a Christian country gospel career (one album, released under the name Katy Hudson in 2005) she reinvented herself as a funny, outspoken pop diva with her 2008 breakout hit I Kissed A Girl.
Although she calls herself a singer-songwriter, she works closely with a team of writer-producers marshalled by Max Martin, the Swedish super producer who helped forge the careers of Britney Spears, Pink and Taylor Swift. Perry has all the vocal chops you might expect from a church raised singer but her USP has been her over-the-top videos built around a brazenly saucy image, establishing her as a sexy but less provocative rival to Lady Gaga.