When Hallie Kuperman founded the Century Ballroom 15 years ago, we were on the brink of a renewed interest in social dancing. And she’s been in the thick of it ever since: teaching everyone who comes through the door, from rank beginners to gifted professionals; offering a beautiful venue for dancers, gay, straight, and in-between. The Ballroom is celebrating its anniversary the way it knows best—with a weekend of dancing from salsa to swing, from country twang to tango. Tonight is a family-style banquet. Saturday is “The Prom” (with all that implies). Sunday features a free all-ages screening of The Rocky Horror Picture Show (with accopanying live stage show). All three events naturally lead to an evening of dancing, so bring a partner or find one at the ballroom. SANDRA KURTZ

Fri., Feb. 24, 7 p.m.; Feb. 25-26, 2012