Clavier-Übung III (German Organ Mass) - Chorale Preludes, BWV 669-689
Johann Sebastian Bach published his Clavier-Übung III (sometimes referred to as German Organ Mass) in 1739. It consists of a collection of works which he started to conceive around the year 1735, and to this day it stands as Bach's most significant and technically demanding set of works for organ. Stylistically, Bach drew inspiration from previous composers such as Palestrina and Frescobaldi, while incorporating modern baroque forms. The result was a compilation that not only acted as a style compendium of organ-writing, but had a didactic dimension to it, as it incorporated a wide range of contrapuntal composition techniques . The German Organ Mass opens and close with a Prelude and a Fugue respectively, enclosing 21 chorale preludes, and four duets. It is common to present these works as separate sub-sets.