“Which comes first—the movie or reality?” wonders Shirley Clarke, playing a fictionalized version of herself in Agnés Varda’s trippy Lions Love (1969). It’s a question Clarke, one of the founding members of the New American Cinema movement, explored in her feature-length films, all of which blur the lines between fiction and documentary: The Connection (1961), The Cool World (1963), and Portrait of Jason (1967, not included in the series). A fine retro offering in the cinematic season of scag (joining Last Days and Olivier Assayas’s upcoming Clean), The Connection centers around a doofus documentarian filming a bunch of junkies waiting for their fix in a decrepit Manhattan loft. What’s most radical about Clarke’s movie isn’t the depiction of the needle and the damage done but her critique of the burgeoning American cinema vérité movement and its claims of capturing “the truth.” Filmed in Harlem with mostly nonprofessional actors, The Cool World features rumbling rival gangs, cutting frequently to real-life scenes (fat men smoking, twisting teenagers) around 120th Street and Fifth Avenue. Clarke’s kinetic vision of New York is also marvelously displayed in two of her rarely screened shorts: the kaleidoscopic Bridges-Go-Round (1958) and Skyscraper (1959), a jazzy ode to the Tishman Building.