The Organ Booklet by Johann Sebastian Bach is a collection of chorale-bound organ pieces (chorale preludes) that he composed primarily during his tenure in Weimar from 1712 to 1717 (BWV 599-644).
The individual movements of the collection are united by a high artistic standard and the idea of usability both in church services and in instrumental and compositional instruction. According to Christoph Wolff, Bach's chorale movements in the Orgelbüchlein are characterized by: "Dense motivic structure and contrapuntal refinement (up to the strict canon) in connection with a bold and expressive musical language as well as subtle musical-theological text interpretation. Each movement achieves proportional balance as manual and pedal voices elegantly combine to create an exemplary organ score."
We hear the chorale prelude
BWV 638 "Es ist das Heil uns kommen her'"
on the sample set of the organ at Lochtum. Since the piece is quite short, it is played 2 times in different disposition.