Cubism and Gleizes. Cubism as a publicly debated movement became relatively unified and open to definition. Its theoretical purity made it a gauge against which such diverse tendencies as Realism or Naturalism, Dada, Surrealism and abstraction could be compared. The Cubism of Picasso, Braque and Gris had more than a technical or formal significance, and the distinct attitudes and intentions of the Salon Cubists produced different kinds of Cubism, rather than a derivative of their work. "It is by no means clear, in any case," wrote Christopher Green, "to what extent these other Cubists depended on Picasso and Braque for their
20th-century classical music explored in their respective articles. At the end of the 19th century (often called the "Fin de siècle"), the Romantic style was starting to break apart, moving along various parallel courses, such as Impressionism and Post-romanticism. In the 20th century, the different styles that emerged from the music of the previous century influenced composers to follow new trends, sometimes as a reaction to that music, sometimes as an extension of it, and both trends co-existed well into the 20th century. The former trends, such as Expressionism are discussed later. In the early part of the 20th century, many composers wrote