Became known forhisthe single«Ur So Gay»,released in 2007,and the internationalhit«I Kissed a Girl»,whichtopped the chartsin many countries, including the U.S., Canada, UK, Australia andIreland.Subsequent singlesCalifornia Gurls, Teenage Dream, Firework, ETandLast Friday Night (TGIF)alsotoppedthe Billboard Hot 100.Perry is thesecondsingerafterMichael Jackson,whosefivesingles fromone albumreached number oneon the U.S. charts.