Allan Kaprow was an American painter and a pioneer of the concepts of performance art. He was also a top of art world in 1960. His famous artwork was “Happening”, but when he moved to San Diego from New York, the place for famous art, he stopped doing “Happening” and started doing “Activities”. His “activity” was walking cross the grass, walk, come back and walk to the grass. When he moved, the environment became active. However, when he stopped, the surrounding was silent. As well as the speed of life, it was too fast, but Allan did not need to be fast like the speed of life. “The “Activities” devoted to the study of normal human activity in a way of congruent to ordinary life” (Wikipedia). About his “Happening”, it “revolutionized the practice of performance art. According to Kaprow, “Art” was not only the picture or artwork hanging on the wall or set on a pedestal, but also the movement, sound, or even scent. His “Happening” was the same category of action in Abstract Expressionists. There were his famous artworks such as Yard (1961), Fluids (1967), Baby (1957), or Trading Dirt (1983).
Source: http://www.theartstory.org/artist-kaprow-allan-artworks.htm#pnt_2 (some information in this website)