With the final release in Vasily Petrenko’s much-lauded Shostakovich cycle on Naxos the young maestro talks to Edward Seckerson about a masterpiece the Soviet authorities tried but failed to sabotage at its first performances. YevgenyYevtushenko’s poem “Babi Yar” with its accusations of anti-Semitism was the flashpoint but social protest runs deep in the piece and nothing in the composer’s output hits home quite as hard or as movingly. It is, in effect, his testimony.