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b. 68

composition: Op. 10 No 10, Etude in A♭ major

d1(2) in A

d1(2) & d1(3) in FE (→GE,EE)

..

The naturals and flats added in FE (→GE,EE) change the chord on which the 1st half of the bar is based. Despite numerous missing accidentals in A, it seems to be highly unlikely that the proofreading was only a correction of an inaccurate notation. Apparently, at the stage of writing A, Chopin heard d from the beginning of bar 68, same as in respective bar 66 (bars 67-68 constitute a modified repetition of bars 65-66).

category imprint: Differences between sources; Corrections & alterations

issues: Authentic corrections of FE

b. 68

composition: Op. 10 No 10, Etude in A♭ major

..

A does not have any accidentals in this bar – see the adjacent note. In a proofreading of FE (→EE,GE1GE2) cautionary flats before a1 and a2 on the 2nd quaver in the bar and before e1 on the 9th quaver (the latter is probably a mistake and we omit it in the main text) were added. In GE3 (→GE4) a  was added before f3 on the 2nd quaver in the R.H., yet also a  instead of a  was inserted in the L.H. (a1 instead of a1).

category imprint: Differences between sources; Editorial revisions

issues: Errors in GE , GE revisions

b. 76-77

composition: Op. 10 No 10, Etude in A♭ major

FE (→EE), literal reading

FE (→EE), suggested interpretation

..

The main text includes the most natural version of A in terms of sound and pianistics. However, the exceptionally thick, spreading traces of the quill's strokes hinder the reading of A in this place, so the version of FE (→EE) differs significantly from the text of A. One's attention is drawn to the absence of stems extending some of the sounds (which can be however easily explained with an oversight) and the ambiguity related to it, as far as the meaning of the tie combining the last a in bar 76 with a relevant semibreve in bar 77 is concerned (in GE both the slur and the semibreve were omitted, which can be a mistake or a revision). The c1 note on the penultimate quaver also raises doubts – the engraver of FE (→GE,EE) could have discerned it on a thick and slightly bulging ledger line, used to write the a note. This version, even if it was not created as a result of Chopin's proofreading intervention, however, could have been accepted by him at the time of going over FE

category imprint: Graphic ambiguousness; Interpretations within context; Differences between sources

issues: Inaccuracies in FE , Authentic corrections of FE , Uncertain notes on ledger lines