The Conductor by Sarah Quigley

In June 1941, Nazi troops march on Leningrad and surround it. Hitler's plan is to shell, bomb, and starve the city into submission. Most of the cultural elite are evacuated early in the siege, but Dmitri Shostakovich, the most famous composer in Russia, stays on to defend his city, digging ditches and fire-watching. At night he composes a new work. But after Shostakovich and his family are forced to evacuate, only Karl Eliasberg - a shy and difficult man, conductor of the second-rate Radio Orchestra - and an assortment of musicians are left behind in Leningrad to face an unendurable winter and start rehearsing the finished score of Shostakovich's Leningrad Symphony.