Working hard is Katy Perry's stock in trade: whether she's cavorting in the Californian sun or heaving her curves, she always lets you see her sweat, even when she's presenting herself as a Teenage Dream, the ideal she puts forth on her 2010 sophomore set. Perry doesn't have great ambitions in mind: all she wants is the spotlight, and she'll follow the path of others to get there, raising eyebrows a'la Alanis, strutting like Gwen Stefani and relying on Britney's hitmaker Max Martin for her hooks. There's no question Perry knows every rule in pop and follows them to the letter: she never breaks away from the expected lite club beats that transition from day-to-night without a hitch or the chilly, stainless steel ballads designed to lose none of their luster on repeat plays. Perry acknowledges some shifting trends -- she salutes Ke$ha on "Last Friday Night (T.G.I.F.)," replicates Ryan Tedder's glassy robotic alienation on "E.T." but tellingly avoids ripping off Lady Gaga -- but these are merely accents to her One of the Boys palette. Perry is at her best when she's delivering sleek singles like "Teenage Dream" and "Hummingbird Heartbeat" with efficiency. ~ Stephen Thomas Erlewine