5th Suite in C minor BWV 1011
Bar 5, 2nd beat (3rd quarter note), we find this "turn" in Anna Magdalena's copy.
Most editions (except Markevitch and Bärenreiter scholarly critical edition) mistook it for quarter rest, but Bach called it "cadence" in the "Explication" in his "Notebook for Wilhelm Friedemann Bach".
Anna Magdalena's quarter rest is like below; it is completely different from "turn".
an example of execution:
From bar 43 to bar 46, it is a little complicated. Kellner and Anna Magdalena are the same, so we can say that is Bach's thought. But the arrangement for lute by Bach himself (BWV 995) is different from them.
I show you another score for better understanding.
Please look at the large noteheads. In Kellner and Anna Magdalena, they are e-flat, e-natural and d-flat, d-natural. In lute arrangement, e-natural, e-natural and d-natural, d-natural. Both are logical and both are beautiful. So we need not change the notes.
Bach did not arrange the 5th suite for lute faithfully. Its typical example is the last chord of Prelude. In Cello Suite, it is major chord but in Lute Suite, minor !
Bar 193, 3rd note, most editions take g according to Anna Magdalena. But Kellner and Lute arrangement show a-natural. Therefore I take a-natural. I suppose Anna Magdalena corrected it from g to a (look at the notehead, she has rewritten it) but she had forgotten to add an accidental.
AllemandeBar 25, there are two problems.
1. First bass note: many editions take b♭, but all sources (4 copies and Lute arrangement) show g unanimously.
It is difficult to understand this chord because there are only three notes. But in the Lute arrangement, Bach wrote five notes. So we can understand easily this chord.
Transposed in C minor:
In the lower figure, first chord is dominant 7th on the tonic, and second chord (as we see in the Lute arrangement) is dominant 7th on the mediant (third degree of the scale). It is less frequent compared to first one, but sometimes is used.
We can see this chord in the other works of Bach; there is an example in The Well-Tempered Clavier, Book 2-3 C♯ major, Prelude bar 11: 1st chord. I transposed it in C major and added the reduction of harmony written by J. S. Bach himself (BWV 872a).
One more example from The Well-Tempered Clavier, Book 2-16 G minor, Prelude bar 12: 1st chord:
Another example from St. Matthew Passion: Finale, bar 11:
From Mass in B minor: Gloria, bar 56:
One more example from Mass in B minor: Quoniam, bar 14 and 91 (musically the same).
2. After the chord above: the rhythm of c-d-b is two 16th notes and a 8th note, not a 8th note and two 16th notes. Kellner and Lute arrangement are the same, therefore it is indisputable.