20th-century classical music describes orchestral works, chamber music, solo instrumental works (including keyboard music), electronic music, choral music, songs, operas, ballets, concertos, symphonies, and related forms, as well as fantasies, rhapsodies, fugues, passacaglias and chaconnes, variations, oratorios, cantatas, suites, improvisational and newly developed formal concepts such as variable and mobile forms, that have been written and performed since 1900. This era was without a dominant style and composers have created highly diverse kinds of music. Modernism , impressionism , post-romanticism , neoclassicism , expressionism , and, later, minimalism were all important movements. Atonality , serialism , musique concrète and electronic music were all developed during this period. Jazz was an important influence on many composers in this period.
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" ( Politoske and Martin 1988 , 419). 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).