With the publication of Volume 11 in November 1999, Werner Breigs fundamentally new scholarly concept begins to make itself felt more strongly. All editorial differences aside: with respect to their contents, Volumes 9-11 can be neatly categorized as the “Tristan letters volumes, the genesis of each act of “Tristan und Isolde” can be assigned to one specific chronological section. Wagner was working on the first act (beginnung his correspondance with Mathilde Wesendonck at the same time) in Zurich during the period of the letters compiled in Volume 9. Volume 10” plays in Venice and documents the origin of the second act. And in Volume 11, the reader can relive the completion of the epoch-making stage work in the letters Wagner sent from Lucerne.