The chorale subject, a German chorale based on Psalm 130, De Profundis, is soloed out on the Rugwerk Dulziaan; two contrapuntal voices sound on G.O. + Pedaal flues.. Tremulant for all. Temperament: Ordinaire. For more Zachau (and Zipoli), please visit http://www.virtuallybaroque.com/list2v.htm