My capacity for buying books exceeds my capacity for reading them; however, I think that this book holds a record, as it was bought about 12 years ago and has gathered more than a bit of dust.
In many ways, this is a book about a book: the controversial 'memoir' by Solomon Volkov, Testimony, which claimed to be the personal recollections of the composer. During his lifetime, Shostakovich was considered in the West to be a faithful Communist: Testimony alleges that he was opposed to the Soviet state at almost every juncture. It's difficult to see how the truth could not lie somewhere in between: the false triumph of the fifth symphony is plain enough, his dislike of Stalin hardly earth-shattering, but how could such a prominent figure live such a lie for so long? I suppose in a totalitarian state the compromises of principle an individual might make are based on very different judgements to our own.
The book is very densely written, from his childhood in between the 1905 and 1917 revolutions, through the progressive 1920s, the Great Terror, the Great Patriotic War, Khrushchev, to Brezhnev and the 1970s. Shostakovich was born into a narodnik family, of the political class of the failed 1905 revolution despised by the Bolsheviks. Despite this, it would appear that Shostakovich was happy enough in the relatively relaxed artisic climate of the 1920s and early 1930s; only after Stalin's diatribe against Lady Macbeth of Mtsensk did he find himself on a collision course with the state. Reprieved with the premiere of his fifth symphony in 1937, ironically, the years of the Great Patriotic War were some of Shostakovich's most free, artistically, until the Zhdanovshchina of 1948. With a cultural thaw after Stalin's death in 1953 Shostakovich was again more free to explore, but the state was never at ease with him, unable to tolerate the acknowledgement of Soviet anti-Semitism in his thirteenth symphony (Babi Yar), but with limited resource to silence him because of his international reputation.
The book also analyses his music as well as his life: the fifteen symphonies form the core of his œuvre, with as many string quartets, various chamber works, and an opera. Sadly the book is fairly dismissive of much of his lighter work for film and theatre, and in this sense it is unbalanced.
Undoubtedly Shostakovich's operatic ambitions were stalled by Stalin's reaction to Lady Macbeth, but that aside, I'm not sure that it is possible to identify significant long-term curtailment of his opportunities for music-making due to the state. It is often said that it is impossible to analyse Shostakovich's music independently of the political conditions under which it was written. I'm not convinced: all composers write under certain political conditions, but most often they are hardly mentioned (an obvious exception is the influence of Napoleon on Beethoven). Shostakovich was unenthused by commissions to celebrate Lenin or the October Revolution, but artists have always been commissioned with some subject material in mind. The book often refers to figures in the literary world, such as Pasternak, Solzhenitsyn, and Akhmatova, but not to the visual arts. Perhaps, as Gerard McBurney has said, it is time to focus on Shostakovich's music rather than his politics.