'A Landmark in Musical History' is John Luke Rose's title for the introduction to this extraordinary piece of theatre. It belongs to the German tradition of mystical writing, and a short note on the poem itself by Martin Swales and Timothy McFarland elucidates some of Wagner's literary techniques. Anthony Negus, who assisted Reginald Goodall on the WNO production of Tristan and Isolde, has contributed a penetrating analysis of the musical structure of the opera, while Patrick Carnegy assesses the remarkable solutions to staging an opera which some argue is best experienced with your back to the performers.