Within the framework of the Sonata da Chiesa the second Sonata is comprised of a prelude and fugue, followed by a cantilena movement in a closely related key and ending with a brilliant finale.​This sonata also exists in a version for the keyboard, BWV 964, in the handwriting of one of Bach’s pupils, Johann Gottfried Muthel 1. Together with a keyboard arrangement of the opening movement from the third violin Sonata, it was found in a collection of manuscripts owned by Johann Christoph Altnickol 2. Although the manuscript is listed in the NBA in a volume of doubtful compositions, we believe that it is Bach’s arrangement; the writing is entirely within Bach’s style and the added counterpoint in the fugue does not seem as though it could possibly be the work of a student. While arranging the Sonatas and Partitas, it was enlightening to compare both versions of this sonata. We saw not only where Bach chose to elaborate on his violin music, but, also, seeing the keyboard version shed light— even more so— on how Bach dealt with the limitations of the violin, and how was able to work within a certain constraint to create these masterful violin solos.

​1. Muthel (1728-1788), a keyboard virtuoso, was Bach's last pupil in the three months before his death in 1750.
2. Alnickol (1720-1759), an organist and composer, studied with Bach from 1744 until 1748. He married Bach's daughter Elisabeth Juliane Friederica in 1749 and became a trustee of Bach's estate.