Trailer for Season 6 of the Peabody Award-winning series, "Art in the Twenty-First Century." Featured artists include: Marina Abramovic, Ai Weiwei, David Altmejd, El Anatsui, assume vivid astro focus, Lynda Benglis, Rackstraw Downes, Glenn Ligon, Robert Mangold, Catherine Opie, Mary Reid Kelley, Sarah Sze, and Tabaimo. Season 6 premieres Friday, April 13, 2012 at 9:00 p.m. on PBS (check local listings). For more information, please visit art21.org.