This is the second of the three works in the appendix of the Breitkopf edition. The critical notes speak of a letter Walther wrote to Heinrich Bokemeyer wherein he expresses that he's not much of an admirer of the Ciacona form, but that this chorale provided an opportunity to show how numerous variations could arise organically from an obligato bass line. If I'm understanding the notes correctly, it is hypothesized that the idea for the work and its compositional form come from Walther, but the actual material may come from his students. The piece is for manuals and pedal.