During the years preceding the composition of Tristan and Isolde, Wagner's aesthetics underwent a momentous turnaround, principally as a result of his discovery of Schopenhauer. Many of Schopenhauer's ideas, especially those regarding music's metaphysical significance, resonated with patterns of thought that had long been central to Wagner's aesthetics, and Wagner described the entry of Schopenhauer into his life as "a gift from heaven." Chafe argues...