6th Suite in D major BWV 1012
Bar 31: 1st bass note is g-sharp, not g (c-sharp, not c in G major). We see it in Kellner's copy. Anna Magdalena has forgotten to write it.
Kellner's copy (attention! the first bar (bar 30) is the alto clef):
in Gavotte 1
In this case, we see it in Anna Magdalena's copy. Bar 7: First bass note is e-sharp, not e (a-sharp, not a in G major) although most editors of Cello Suites neglect it. (But the highest note of the last chord is a mistake. It is not e, but c-sharp)
Both sharps form natural chromatic processions of bass and both sharps are so charming, aren't they?
In the case of Sarabande, it corresponds to preceding chromatic procession of bass (bar 28 - 29).
It is very interesting that all the later sources are different from each other about bar 31 of Sarabande.
We can imagine Source G (the matrix of these three sources; see Preface) was the same as Anna magdalena. But the copyists of Sources C and D were not content with it. Yes, they are right. I show you last three bars of Anna Magdalena's copy (= Source G) by omitting all the rests and anticipations.
We understand easily that extended g of bass is too long, unnatural. It must be changed into another note at the second bar. The copyists of Sources C and D tried each solution. Paris first edition (and naturally Source E) did not change it.