This opera, with music by Michael Nyman, begins with a straightforward rendition of a story from neurologist Oliver Sacks, who recounts how a progressive brain disorder has so skewed a music professor's ability to recognize objects that he quite literally becomes The Man Who Mistook His Wife for a Hat. The opera based on that story is then screened, with tenor Emile Belcourt playing the doctor, baritone Frederick Wescott as the misperceiving professor, and soprano Patricia Hooper as the hat-like wife. Though the professor's perceptions are diminished in one respect, he never loses his ability to teach music, or to play chess in his head -- though he cannot distinguish the actual chess pieces on the board.