y 21st St: Thomas Hirschhorn: DE-PIXELATION MoMA, New York: Club 57: Film Performance and Art in the East Village 1978-1983 Nancy Hoffman Gallery: Joseph Raffael - opens Thu, 26 Oct Paula Cooper Gallery, 534 W. 21st St: Cecily Brown: A Day! Help! Help! Another Day! Sean Kelly Gallery: David Claerbout: The p