Though musically they are worlds apart, Shostakovich's Second and 12th Symphonies make a logical pairing, for both are celebrations of the 1917 Russian revolution, the Second was composed to mark the 10th anniversary in 1927, a time when artistic radicalism was still actively encouraged in the fledgling Soviet Union; though he later disowned the score it represents Shostakovich's closest approach to modernism, even if its choral finale, launched by the sound of a factory whistle, sets a blatantly propagandist text.
The 12th is arguably the weakest of all the symphonies, though Mariss Jansons' performances give both pieces the benefit of the doubt; he manages to make even the contrived finale of the 12th sound convincing.