Sol LeWitt, who once worked as a draftsman for I. M. Pei, has said of his own directions for drawings executed by collaborators that, "The contribution brought by the draftsman may not be predicted by the artist, even when the artist is also the draftsman." This separation of the plan, the written score for a work, from its execution and the finished piece lies at the center of the work for which LeWitt is best known, whose execution he entrusts to strangers. "Wall Drawings" tracks the creation of one recent work, beginning with the plan, so spare that it looks as though it might have arrived at the gallery by fax, and continuing through to a schematic drawing on the wall, then figures on stepladders drawing intently, their faces clear but their pencils blurred. Close-ups of their scribbles and images of the completed work are followed by a picture of the triumphant cast, a curtain call.