Hugo Riemann's famous frontmatter - a Verzeichnis der Druckausgaben (Catalog of printed editions) and Thematischer Katalog (Thematic Catalogue) - to the first volume of the collection of symphonies by composers of the Mannheim school, issued in 1902 as Jahrgang III of the Denkmäler der Tunkunst in Bayern. Riemann's catalog contains much more than the symphonies which appeared in the DTB volumes and is even useful now for these mid-18th century composers, whose original editions featured a mass of conflicting and repeated opus numbers. This except starts with biographies of the more important composers represented.