20th century classical music begins with the late Romantic style of Sergei Rachmaninoff, Impressionism of Claude Debussy and Maurice Ravel, American Vernacular music of Charles Ives and George Gershwin, and continues through the Neoclassicism of middle-period Igor Stravinsky, the twelve-tone music of Arnold Schoenberg, Alban Berg, and Anton Webern.
Perhaps the most salient feature during this time period of classical music was the increased use of dissonance. Because of this, the twentieth century is sometimes called the "Dissonant Period" of classical music, which followed the common practice period, which emphasized consonance.
The twentieth century was also an age where recording and broadcast changed the economics and social relationships inherent in music. An individual in the 19th century made most music themselves, or attended performances. An individual in the industrialized world had access to radio, television, phonograph and later digital music such as the CD.