The full title of “The Cotillion,” Colette Robert’s new play with music, is “The Harriet Holland Social Club Presents the 84th Annual Star-Burst Cotillion in the Grand Ballroom of the Renaissance Hotel,” and that exaggerated, super-elegant, ultrarefined sensibility—the centerpieces are tasteful, the gowns are divine—conveys the aesthetic for the playwright’s blistering, all-caps discussion of Black élite debutante culture. In this co-production from New Georges and the Movement Theatre Company (at A.R.T./New York Theatres, through May 27), we spend an evening with six poised (or trying to be poised) seventeen-year-olds as they make their long-awaited début, all while their chapter’s president (Akyiaa Wilson, excellent in moral decay) undermines them with colorist, oligarchic, puritanical concerns. Robert, who also directs, destabilizes the reality in the ballroom: characters accidentally refer to “auctions” during the ugliest parts of the beauty parade, and the world glitches and stutters like a horror film. As much as Robert wants to show us the skull beneath the updo, though, she’s also dedicated to the loveliness of the event: songs (written by Dionne McClain-Freeney) decorate the play, performed by a glittering doo-wop quartet, who sing about sex, power, and Blackness with a sangfroid the teen-agers have yet to discover.