After World War II, promising composers seemed to appear like magic from almost every corner of the globe. Among the leaders from France, Germany, and Italy were Olivier Messiaen (1908–1994), Pierre Boulez (b. 1925), Karlheinz Stockhausen (1928–2007), and Luciano Berio (1925–2003). They were joined by the Poles Witold Lutosławski (1913–1994) and Krzysztof Penderecki (b. 1933), the Hungarian György Ligeti (1923–2006), the Greek Iannis Xenakis (1922–2001), the Americans Milton Babbitt (1916–2011), John Cage (1912–1992), and Elliott Carter (1908–2012), and the Japanese Toru Takemitsu (1930–1996).

The history of music in the second half of the twentieth century is saturated with the works of these composers. Their music resonates with the anxiety and turmoil of the era, celebrating its triumphs and mourning its tragedies; it would be impossible to maintain that the music of Boulez, Ligeti, and Takemitsu is any less varied, intense, moving, or magnificent than that of any other like period of music history. Yet as the twenty-first century gets under way, by and large the music of these composers has not found its way into the experience of most ordinary listeners. There are many reasons for this, both sociological and aesthetic, which we cannot take up here. As we have seen, modernism’s first phase — the phase just before World War I — produced works that now count as “classics”: Berg’s Wozzeck, a fixture in the opera house; Bartók’s six string quartets, played by every professional string quartet; and Stravinsky’s The Rite of Spring, an all-time favorite on recordings. For acknowledged masterpieces written after World War II, however — such as Boulez’s song cycle Le Marteau sans maître (The Hammer without a Master) or Berio’s Sinfonia — similar acceptance has been slow in coming.