There are at least two moments of indisputable greatness in Wagner’s Tannhauser: The act 2 intervention by Elizabeth to save Tannhauser’s life from the likes of Biterolf and his cruel and cowardlycohorts, and Tannhauser’s act 1 epiphanyin the valley of the Wartburg, with the unforgettable, immortal counterpoint of the shepherd boy’s lovely melody, fresh as May: “Der Mai! Der Mai!”