This document provides an overview of Western music in the 20th century, focusing on several major styles and composers. It discusses impressionism and key impressionist composers like Debussy and Ravel. It then covers atonality and the 12-tone technique developed by Schoenberg. Other styles mentioned include primitivism, neo-classicism, and avant-garde music. Specific composers highlighted include Stravinsky, Bartok, Prokofiev, Poulec, and American composers like Gershwin and Bernstein who incorporated jazz elements. Videos are provided as examples of major works for many of the composers and styles.