No matter that both your feet are lefties. “Midsummer Night Swing” will get them stepping and gliding with rhythm, grace, and spunk. Just one painless group lesson with a couple of pros—right now, Pierre Dulaine and Yvonne Marceau, of American Ballroom Theater fame—cajoles you out of your klutziness or shyness. And there you are, outdoors at twilight on Lincoln Center Plaza, dancing away to swell live music—tonight from George Gee’s Swingin’ Big Band—along with accomplished amateurs, utter newbies, and other New Yorkers looking for love. (Some actually find life partners here.) The crowd of the moment takes swing’s jaunty basics—bouncy pacing punctuated with breezy little kicks and swirls under the trellis of a partner’s arm—and embroiders them with private fantasies. Yet the whole place throbs with a firm communal rhythm; it might be the heartbeat of joy. Future sessions feature myriad forms that started out in Latin America or Africa, as well as jazz both hot and bluesy, country-western (urban cowgirls and their guys), and even Irish clogging. Be there.