Short answers, pulled from the story.
Modernism was an early 20th-century movement in literature, visual arts, performing arts, and music that emphasized experimentation, abstraction, and subjective experience. It is characterized by a self-conscious rejection of tradition and the search for newer means of cultural expression. It also touched philosophy, politics, architecture, and social issues.
Modernism emerged during the late 19th century in response to significant changes in Western culture, including secularization and the growing influence of science. The first wave of modernist works appeared in the opening decade of the 20th century, and by 1930 Modernism had won a place in the political and artistic establishment.
The Great War of 1914 to 1918 and the Russian Revolution of 1917 cast doubt on the beliefs and institutions of the past. The senseless slaughter made the view of steady moral progress seem ridiculous, so Modernism's view of reality, a minority taste before the war, became more generally accepted in the 1920s.
The Nazi regime in Germany adopted the term degenerate art for virtually all modern art, banning it as un-German or Jewish Bolshevist in nature. Degenerate Art was also the title of an exhibition the Nazis mounted in Munich in 1937, and identified artists were dismissed from teaching, forbidden to exhibit or sell, and in some cases forbidden to produce art.
Modernism is associated with abstract art, Cubism, and the rejection of a single point of view, as in Pablo Picasso's 1907 painting Les Demoiselles d'Avignon. In Cubist artwork, objects are analyzed, broken up, and reassembled in abstract form, depicting a subject from a multitude of viewpoints rather than one.
Modernist architects and designers such as Frank Lloyd Wright and Le Corbusier believed new technology rendered old styles obsolete, with Le Corbusier arguing buildings should function as machines for living in. The skyscraper became the archetypal modernist building, from the Wainwright Building of 1891 in St. Louis to Ludwig Mies van der Rohe's Seagram Building in New York, built from 1956 to 1958.