This year marks 50 years since the death of Dmitri Shostakovich, Soviet Russia’s most distinguished composer. Fans have been relishing a whole year’s anniversary programming, while the Fifth, 10th and 13th Symphonies, the First Cello Concerto and the grisly opera Lady Macbeth of Mtsensk were performed during this summer’s BBC Proms. Still, unlikely to be programmed widely — if at all — is “The Song of the Counterplan”, arguably Shostakovich’s most successful composition and certainly the best-known during his lifetime.