The heroine of the opera, Katerina Ismailova, becomes by her situation and actions the ‘Lady Macbeth of Mtsensk’ of the story from which Shostakovich drew his libretto. She is trapped in a loveless, heirless marriage, and takes a lover who is caught and flogged by her father-in-law. In revenge she doses the latter’s mushrooms with rat poison and he dies, but not before naming her to the priest as his murderess. As this scene ends (Act II, Scene 4) the Passacaglia crashes in, a massive evocation of the forces in which Katerina is entangled. This arrangement of the Passacaglia for organ is by the composer.
from notes by Ian Carson © 1992