The Avant-gardes refer to innovative trends (tendenze) in arts and in the cultural realm in general. The most famous were born together with Modernism in the first decades of the 20thcentury. It is quite difficult to define avant-guard movements . The Italian essayist (saggista) Renato Poggioli in his 1962 book Teoria dell’arte d’avanguardia (The Theory of the Avant-Garde) states (dice) that vanguardists share (condividono) non-conformist ideals or values. Clement Greenberg in his essay Avant-Garde and Kitsch ( 1939) wrote that vanguard culture has historically been opposed to “high” or “mainstream” culture (cultura di tendenza), and that it has also rejected the artificially synthesized mass culture (cultura di massa sintetizzata) that has been produced by industrialization. This view was also supported by the Frankfurt School – Theodor Adorno, Max Horkheimer , Walter Benjamin. They saw the avantguards as opponents of the industrial-capitalistic method which only considered masterpieces (capolavori) the commercial bestsellers (più venduti). The most influential avant-garde figures in English-language literature include Gertrude Stein, James Joyce, Ezra Pound, William Carlos Williams, Louis Zukofsky, Charles Olson, William Gaddis, John Hawkes, John Ashbery, Joseph McElroy, Stanley Elkin, John Barth, Robert Coover, Kathy Acker, Giannina Braschi, and Thomas Pynchon. As to visual arts among the most famous artists are Salvador Dalì, Pablo Picasso, Man Ray, Paul Gaugin…..