Conceptual art is a movement that prizes ideas over the formal or visual components of art works. An amalgam of various tendencies rather than a tightly cohesive movement, Conceptualism took myriad forms, such as performances, happenings, and ephemera. From the mid-1960s through the mid-1970s Conceptual artists produced works and writings that completely rejected standard ideas of art. Their chief claim – that the articulation of an artistic idea suffices as a work of art – implied that concerns such as aesthetics, expression, skill and marketability were all irrelevant standards by which art was usually judged. So drastically simplified, it might seem to many people that what passes for Conceptual art is not in fact “art” at all, much as Jackson Pollock’s “drip” paintings, or Andy Warhol’s Brillo Boxes (1964), seemed to contradict what previously had passed for art. But it is important to understand Conceptual art in a succession of avant-garde movements (Cubism, Dada, Abstract Expressionism, Pop, etc.) that succeeded in self-consciously expanding the boundaries of art. Conceptualists put themselves at the extreme end of this avant-garde tradition. In truth, it is irrelevant whether this extremely intellectual kind of art matches one’s personal views of what art should be, because the fact remains that Conceptual artists successfully redefine the concept of a work of art to the extent that their efforts are widely accepted as art by collectors, gallerists, and museum curators.