The organ works of Franz Tunder consist of four preludes, one canzon and nine chorale settings. The works constitute an important stylistic link between Sweelinck and Buxtehude. On the basis of new findings on sources, stylistic aspects and performance practice of 17th-century organ music, Michael Belotti provides a new assessment of Tunders works and offers many new solutions concerning dubious or fragmentarily transmitted passages. In many cases, however, the editor decided to simply follow the sources, since they are superior to the attempted improvements of the earlier editions. For this reason too, Belottis new Urtext edition deserves the predicate very close to the sources.