The 3rd book of the Clavierubung was the first collection of organ music published by J S Bach, and is his largest collection of works for the organ. The 1st part of the Clavierubung appeared in 1731 and consisted of the Partitas BWV 825-830 (published as his Opus1), and was followed by the 2nd part in 1735 which included such well know works as the Concerto in the Italian Style and the French Overtures BWV 831 and 971. Parts 1&2 are for harpsichord, the latter for an instrument with 2 keyboards.

The 3rd part calls for an instrument with 3 keyboards (i.e the organ pedals), and requires an organist of considerable ability to perform its works. It is interesting that the inscription refers specifically to connoisseurs, a reference to the greater ability required from the performer.

This is Bach’s magnum opus for organ.

Instruments:
- Christoph Treutmann, organ, 1737, in the Abbey Church in Grauhof/Goslar
- Johann Scheibe, organ, 1746, in the Parish Church of Zschortau/Leipzig
- Heinrich Gottfried Trost, organ, 1724–30 in the Town Church of Waltershausen