Not many pop stars can quote “The Great Gatsby” in a suit and tie onstage, then climb onto a balcony while striking poses and spanking themselves. But Pulp frontman Jarvis Cocker did all that, and more, as part of his act at Radio City Music Hall on Tuesday, when his reunited band played here for the first time in 14 years. “I know it’s a corny thing bands say: ‘We love your cit-ayy!’ ” Cocker said, “But it made me want to cry a little bit walking around here . . . and the bathrooms are really nice.” Rolling Stone’s Rob Sheffield aptly described Cocker in a review of the gig as “a brazen showgirl in the body of a pervy librarian.” Alexa Chung and Bravo’s Bill Powers were spotted in the crowd. The Britpop band played Radio City again last night before heading to Coachella tomorrow with the Black Keys, Madness, Arctic Monkeys and Swedish House Mafia.