Ke$ha’s main competitor rocks a mean meat dress, but can she rock a couplet like “Your little heart goes pitter-patter/I want your liver on a platter”? This EP proves Ke$ha would kick Gaga’s ass in a freestyle battle. At times — rhyming “go insane” with “see them Hanes” over squishy techno on “Blow” — that’s enough. Ke$ha lives and dies by the wisecrack; “Grow a Pear” suggests the word “mangina” will never work in a pop song. She can go deeper when she wants to — see “The Harold Song,” a lament about sleeping in an empty bed. But that’s not why we’re here. It’s for jams like the awesome, Dr. Luke-produced “We R Who We R.” Cheekily celebrating dance-induced dumbness over a huge hook, she’s the snap queen of clubland.