June 1941: Nazi troops surround the city of Leningrad, planning to shell and starve the people into submission. Most of the cultural elite is evacuated, but the famous composer Shostakovich stays behind to defend his city.

That winter, the bleakest in Russian history, the Party orders Karl Eliasberg, the shy, difficult conductor of a second-rate orchestra, to prepare for the task of a lifetime. He is to conduct a performance of Shostakovich's Seventh Symphony - a haunting, defiant new piece, which will be relayed by loudspeakers to the front lines.

Eliasberg's musicians are starving, and scarcely have the strength to carry their instruments. But for five freezing months the conductor stubbornly drives on his musicians, depriving those who falter of their bread rations. Slowly the music begins to dissolve the nagging hunger, the exploding streets, the slow deaths... but at what cost? Eliasberg's relationships are strained, obsession takes hold, and his orchestra is growing weaker. Now, it's a struggle not just to perform but to stay alive.