This document provides an overview of several 20th century classical music composers and styles. It mentions Sergei Prokofiev and his works like Cinderella and Peter and the Wolf. It also discusses Dmitry Shostakovich and his symphonies. Expressionism and composers like Schoenberg, Berg and Webern are covered. It introduces serialism and 12-tone composition. Styles like neoclassicism are also summarized along with composers like Manuel de Falla, Arthur Honegger, Francis Poulenc, Darius Milhaud and Paul Hindemith.