The Dance Theatre of Harlem, one of America’s “leading dance institutions”, will perform at New Rochelle High School on Sept. 24 as part of ArtsFest, the weekend long celebration of the arts in New Rochelle (visit www.newrochellearts.org for a complete calendar). The DTH Ensemble will perform a free, hour long “behind the scenes” look at how dances are choreographed from 2 to 3:15 pm in the high school’s Linda Kelly Theater, and the public is invited to observe the company in open rehearsals from 3:30 to 5:30 p.m. that afternoon. Later that evening New Rochelle resident Michael Armstrong, Senior Vice President and General Manager of BET International, and his wife Lori Hall Armstrong will host a benefit event, which will include an extraordinary performance by the Dance Theatre of Harlem Ensemble and a reception afterward. Seating is limited; tickets are available from http://www.eventbrite.com/event/2007762271.