The first episode looks at the shift in the language and sound of music from the beautiful melodies and harmonies of the giants of classical music such as Mozart, Haydn and Brahms into the fragmented, abstract, discordant sound of the most radical composers of the new century - Schoenberg, Webern, Stravinsky and beyond. It examines how this new music, which can perplex and upset even the most contemporary of audiences, was a response to the huge upheaval in the world at the start of the 20th century - with its developments in technology, science, modern art and the tumult of the First World War.
The second episode looks at how the freewheeling modernism that had shocked, scandalised and titillated audiences in the first two decades of the 20th century comes under state control. Initially, many practitioners thought the totalitarian regimes would be good for music and the arts. What followed in Germany was a ban on music written by Jews, African-Americans and communists, while in the Soviet Union there was a prohibition on music the workers were unable to hum. In the USA, many composers voluntarily embraced music for the masses. After the cataclysm of the 1940s, a new generation of 20-something composers - Boulez, Stockhausen, Xenakis, Nono, Ligeti - turned their back on what they saw as the discredited music of the past and decided to try and reinvent it from scratch. Or, at least, from serialism, which became, as the 1950s wore on, as much of a straitjacket as the strictures of totalitarianism had been before.
The series concludes with the focus shifting to the United States in the post-war years of the 1950s and beyond. Beginning with arguably the most notorious work of 20th century classical music, John Cage's 'silent' composition 4'33", it looks at how a series of maverick Americans re-invented the sound of classical music into a more simple form, bringing back harmonies and rhythms that made it increasingly popular with audiences across the world. It also examines how this music found its way into a spiritual realm, with the strain of pared-down religious composition that came to be known as 'holy minimalism'. From the Maverick concert hall in Woodstock, New York to an Orthodox cathedral in Estonia to a car park in Peckham, south London, the story is told by a stellar line-up of contributors including Philip Glass, Steve Reich, John Adams, Arvo Pärt and John Tavener.