Katy Perry has cemented her status as a best-selling superstar with the global success of her second studio album, Teenage Dream, which debuted at #1 in 8 countries. With her third single, "Firework," spending four weeks at #1, she becomes the first female artist in 11 years to score three number one singles from the same album on Billboard's Hot 100 ("California Gurls" reigned for 6 weeks, while "Teenage Dream" topped the chart for 2 weeks). This follows on the heels of her multi-platinum debut album, One of the Boys, which had generated four hit singles: "I Kissed A Girl," "Hot N Cold," "Thinking of You" and "Waking Up In Vegas." She wrapped up 2010 in style with 4 Grammy nominations, including one for "Album of the Year." Katy kicks off her California Dreams Tour at the beginning of 2011, with stops in Europe, Australia, New Zealand, Japan, North America and beyond.