Music has changed more in the 20th century than in any previous one: the gulf between 1800 (Beethoven's First Symphony, Haydn's The Seasons) and 1900 (Elgar's The Dream of Gerontius, Mahler's Fourth Symphony) is easier to bridge than that between 1900 and 1913 (Stravinsky's The Rite of Spring). Within ten years of Stravinsky's masterpiece, Arnold Schoenberg brought about another, even more revolutionary change. In less than a quarter of a century music had been radically transformed, and it has continued to evolve at an accelerating pace. Since the 1970s styles and isms have proliferated to an extent that even professional critics and music historians can barely keep up. How, then, can the layman understand what has happened? Linked to a BBC Radio 3 series, this book aims to take a new approach to the story of music in the 20th century, concentrating on the forces which have formed it. Social and economic change, technological developments, political upheavals, and new attitudes to non-western and popular music are among the factors that, according to the book, have been as profound an influence as any of the century's great composers. The book is based on the words of some of those who created the century's music, drawn from interviews carried out for the radio series, and from the BBC's sound archives.