From Picasso's Cubism and Duchamp's readymades to Warhol's silkscreens and Smithson's earthworks, the art of the twentieth century broke completely with earlier artistic traditions. A basic change in the market for advanced art produced a heightened demand for innovation, and young conceptual innovators - from Picasso and Duchamp to Rauschenberg and Warhol to Cindy Sherman and Damien Hirst - responded not only by creating dozens of new forms of art, but also by behaving in ways that would have been incomprehensible to their predecessors.

In the fateful year of 1913, events in New York and Paris launched a great public rivalry between the two most consequential artists of the twentieth century, Pablo Picasso and Marcel Duchamp. The New York Armory Show art exhibition unveiled Duchamp’s Nude Descending a Staircase, a “sensation of sensations” that prompted Americans to declare Duchamp the leader of cubism, the voice of modern art.