19. Wall/Floor Positions by Bruce Nauman, 1968
Among the most innovative early performance artists utilizing video, Bruce Nauman stands out for his infamous epiphany: "If I was an artist and I was in the studio, then whatever I was doing in the studio must be art. At this point art became more of an activity and less of a product." He began using his body to explore the particulars of space, notably in the 60-minute film Wall-Floor Positions. Here, Nauman contorted into various positions in relation to his studio, becoming the very material he would sculpt.