The factors that would make Katy Perry a worldwide phenomenon—offbeat lyrics, teasing sexuality, silliness, and that surprisingly deep purr—are fully in place on her debut album, One of the Boys. The provocative dance-rock jam “I Kissed a Girl” and the pointedly playful “Ur So Gay” may set tongues wagging (so to speak), but they'll also loosen jaws for the suckerpunch of “Hot n Cold,” a giddy rollercoaster of a song that makes skewering a half-hearted boyfriend sound like the most fun a girl could ever have.