The Soviet Union’s most famous composer took a sea voyage to America near the end of his life. This remarkable documentary is structured around his days on a Russian cruise ship in 1973. Soviet historical and propaganda footage form a visual counterpoint to a world-weary narration. Ample quotations from Dmitry Shostakovich’s writings give a window to his life story, which also spans twentieth century musical and world history. Unusual footage from his musical works, such as the operas “The Nose” and “Lady Macbeth,” are highlights in an elliptical and experimental tour de force.  NK