Clavier-Übung III is considered Johann Sebastian Bach’s most important and most complete organ work, containing some of his pieces for the instrument that are the most complex musically and the most demanding technically. Formally, it takes its inspiration from the religious music of the masters of the stile antico. But, at the same time, Bach was an innovator and here incorporated modern Baroque musical forms, such as the chorale à la française and the gallant style. The aim of the collection was manifold: an ideal organ programme; a practical translation of Lutheran doctrine in musical terms for devotional use at church or in the home; a collection of organ music in all possible styles and idioms, old and modern; and a didactic work presenting examples of all possible forms of contrapuntal composition, going well beyond earlier treatises of musical theory. Léon Berben gives us his interpretation, a new and fresh view of this milestone in organ music, using the exceptional sound colours of an organ contemporary with Bach and largely preserved in its original state: the Christoph Treutmann organ in Grauhof (Germany).