John Clem Clarke, a young star during the glory days of the SoHo art scene in the 1960s and '70s and an early practitioner of pop art who went on to keep that aesthetic movement and his Manhattan neighborhood's bohemian spirit alive into the 21st century, died June 5 at a nursing home in Keizer, Oregon. He was 83. In the 1970s, Clarke earned comparisons to figures now considered modern masters, like Andy Warhol, Roy Lichtenstein and Robert Rauschenberg, for the wit with which he made what critics called "art about art" and for an aesthetic style that incorporated the techniques of industrial mass production. He became known for reinterpretations of canonical paintings. Using a projector, he broke down images of those paintings into stencils and used sponges or homemade spray-paint cans to paint a canvas. His distorted masterpieces looked blurred or brightened, dilated or flattened. In the 1960s, he devoted an entire show to reproductions of American painter John Singleton Copley's staid "Portrait of Mr. and Mrs. Thomas Mifflin" (1773). In several takes, Clarke washed out the skin pigmentation of the two human figures, rendering the couple in an eerie alabaster hue. Clarke wanted his style to convey the vibrancy he saw in American pop culture. His introduction to art came through comic books and textbooks.