A Life for the Tsar
Tchaikovsky actually derived his "fate" theme from a passage in Glinka's opera "A Life for the Tsar"—significantly, a passage in the libretto using the words "turn not into sorrow." Shostakovich heightens its appearance by quoting it not in its initial tonality but in the key of its heroic triumph at the symphony's conclusion. This gesture shows the march, at the peak of hysteria, as Russian rather than German. It also shows Shostakovich has controlled the march's ambiguity all along.