The crossings-out visible in As reveal that the bottom voices of the chords in the 2nd half of the bar were changed twice. The initial version, which was crossed out, continued the previous harmonic filling of b. 19-21 (see the note in b. 19):
. Having forgone the accompaniment in the preceding bars, Chopin also crossed out the bottom notes of the crotchet chords, which resulted in a precise gradation of the number of voices: from one in b. 20, through two in the 1st half of b. 21, three and four in the 2nd half, to five and six in b. 22. In the final version, that effect was abandoned in favour of a bass line referring to the quaver figures in b. 18-19, like they refer – also preceded by a rest – to b. 15-16.
Compare the passage in the sources»
category imprint: Differences between sources; Corrections & alterations
issues: Chopin's hesitations, Accompaniment changes
notation: Pitch