From the anguished harmonies of its prelude to Tristan’s deathbed hallucinations and Isolde’s transcendent Liebestod, the third act of Wagner’s Tristan und Isolde is mesmerizing. Jonas Kaufmann and the Boston Symphony Orchestra conducted by Andris Nelsons won outstanding reviews for their performance of the opera’s second act in 2018. The New York Times said Kaufmann’s singing “combines virile energy with dusky colorings” and is “what you dream of hearing when Tristan sings.” Hear how the story ends and be moved.