 The concept of avant-garde refers primarily to artists, writers, composers and thinkers whose work is opposed to mainstream cultural values and often has a trenchant social or political edge.Many writers, critics and theorists made assertions about vanguard culture during the formative years of modernism, although the initial definitive statement on the avant-garde was the essay "Avant-Garde and Kitsch" by New York art critic Clement Greenberg, published in "Partisan Review" in 1939.Greenberg argued that vanguard culture has historically been opposed to "high" or "mainstream" culture, and that it has also rejected the artificially synthesized mass culture that has been produced by industrialization.