As was the case with bars 1 and 5, the AsI version of the last note of the 4th hemidemisemiquaver group in bars 17 and 21 (written down as a repetition of the preceding one) is a transitional stage between the initial version featuring B1 as the last bass note in these bars and the final version present in A.
Compare the passage in the sources »
category imprint: Differences between sources; Corrections & alterations; Source & stylistic information
issues: Accompaniment changes, Corrections of AI
notation: Pitch