Painter Marcel Duchamp (28 July 1887 - 2 October 1968, was a French artist whose work is most often associated with the Dadaist and Surrealist movements. Duchamp's output influenced the development of post-World War I Western art. He advised modern art collectors, such as Peggy Guggenheim and other prominent figures, thereby helping to shape the tastes of Western art during this period. A playful man, Duchamp challenged conventional thought about artistic processes and art marketing, not so much by writing, but through subversive actions such as dubbing a urinal "art" and naming it Fountain. He produced relatively few artworks, while moving quickly through the avant-garde circles of his time. The creative act is not performed by the artist alone; the spectator brings the work in contact with the external world by deciphering and interpreting its inner qualifications and thus adds his contribution to the creative act. Marcel Duchamp, French Dada artist, whose small but controversial output exerted a strong influence on the development of 20th-century avant-garde art. Born on July 28, 1887, in Blainville, brother of the artist Raymond Duchamp-Villon and the painter Jacques Villon, Duchamp began to paint in 1908. After producing several canvases in the current mode of Fauvism, he turned toward experimentation and the avant-garde, producing his most famous work, Nude Descending a Staircase, No. 2 (Philadelphia Museum of Art) in 1912; portraying continuous movement through a chain of overlapping cubistic figures, the painting caused a furor at New York City's famous Armory Show in 1913. He painted very little after 1915, although he continued until 1923 to work on his masterpiece, The Bride Stripped Bare by Her Bachelors, Even (1923, Philadelphia Museum of Art), an abstract work, also known as The Large Glass, composed in oil and wire on glass, that was enthusiastically received by the surrealists. In sculpture, Duchamp pioneered two of the main innovations of the 20th century kinetic art and ready-made art. His "ready-mades" consisted simply of everyday objects, such as a urinal and a bottle rack. His Bicycle Wheel (1913, original lost; 3rd version, 1951, Museum of Modern Art, New York City), an early example of kinetic art, was mounted on a kitchen stool. After his short creative period, Duchamp was content to let others develop the themes he had originated; his pervasive influence was crucial to the development of surrealism, Dada, and pop art. Duchamp became an American citizen in 1955. He died in Paris on October 1, 1968.