Hot n Cold

Released September 9, 2008 as the second single from One of the Boys, Hot n Cold turned Katy Perry from a one-hit wonder into a bona fide pop star. Co-written with Dr. Luke and Max Martin, the song's bouncy synth hook and playful lyrics about a flaky partner hit a nerve worldwide. It peaked at number three on the Billboard Hot 100 and spent 34 weeks on the chart, eventually going 3x Platinum in the US.

Internationally, the track was even bigger. It topped charts in Austria, Canada, Denmark, Finland, Germany, Ireland, Norway, Sweden, and Switzerland. In the UK it reached number four and earned Platinum certification. The music video, directed by Alan Ferguson, shows Perry as a bride whose groom keeps changing his mind, a visual that's racked up over 300 million YouTube views.

Critics loved the chorus. Billboard called it a playful, synth-driven pop confection, while Rolling Stone highlighted its irresistible hook. It earned a Grammy nomination for Best Female Pop Vocal Performance in 2010 and won Pop Song of the Year at the 2009 BMI Pop Awards. The song has been covered by artists like The Baseballs and the cast of Glee, and appeared in films including The Hangover.[edit]