20th-century classical music describes art music that was written nominally from 1901 to 2000, inclusive. Musical style diverged during the 20th century as it never had previously, so this century was without a dominant style. Modernism, impressionism, and post-romanticism can all be traced to the decades before the turn of the 20th century, but can be included because they evolved beyond the musical boundaries of the 19th-century styles that were part of the earlier common practice period. Neoclassicism and expressionism came mostly after 1900. Minimalism started much later in the century and can be seen as a change from the modern to postmodern era, although some date postmodernism from as early as about 1930. Aleatory, atonality, serialism, musique concrète, electronic music, and concept music were all developed during the century. Jazz and ethnic folk music became important influences on many composers during this century. History At the turn of the century, music was characteristically late Romantic in style. Composers such as Gustav Mahler, Richard Strauss and Jean Sibelius were pushing the bounds of post-Romantic symphonic writing. At the same time, the Impressionist movement, spearheaded by Claude Debussy, was being developed in France. Debussy in fact loathed the term Impressionism: "I am trying to do 'something different—in a way realities—what the imbeciles call 'impressionism' is a term which is as poorly used as possible, particularly by art critics". Maurice Ravel's music, also often labelled as impressionist, explores music in many styles not always related to it (see the discussion on Neoclassicism, below). Many composers reacted to the Post-Romantic and Impressionist styles and moved in quite different directions. The single most important moment in defining the course of music throughout the century was the widespread break with traditional tonality, effected in diverse ways by different composers in the first decade of the century. From this sprang an unprecedented "linguistic plurality" of styles, techniques, and expression. In Vienna, Arnold Schoenberg developed atonality, out of the expressionism that arose in the early part of the 20th century. He later developed the twelve-tone technique which was developed further by his disciples Alban Berg and Anton Webern; later composers (including Pierre Boulez) developed it further still. Stravinsky (in his last works) explored twelve-tone technique, too, as did many other composers; indeed, even Scott Bradley used the technique in his scores for the Tom and Jerry cartoons. After the First World War, many composers started returning to