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b. 20

composition: Op. 10 No 9, Etude in F minor

No mark in AI

Long accent in A & EE

Short accent in FE (→GE)

..

The unambiguous long accent in A was interpreted in FE (→GE) as short. However, the mark in EE may be regarded as long.

category imprint: Differences between sources

issues: Long accents

b. 20

composition: Op. 10 No 9, Etude in F minor

category imprint: Differences between sources; Corrections & alterations

b. 21-23

composition: Op. 10 No 9, Etude in F minor

..

The sources are missing some of the flats before g notes (in various octaves). None of these inaccuracies raise any doubt concerning the sound intended by Chopin. In AI there are no  before g, as well as before G and g1 in bar 23. In A both flats in the L.H. in the 2nd half of bar 22 are missing; only the first of them was added in FE. The remaining sources have the correct text. 

category imprint: Interpretations within context; Differences between sources

issues: EE revisions , Accidentals in different octaves , Inaccuracies in FE , GE revisions , Omission of current key accidentals , Authentic corrections of FE , Inaccuracies in A

b. 21-26

composition: Op. 10 No 9, Etude in F minor

..

In AI there are no verbal indications in these bars.

category imprint: Differences between sources

b. 22

composition: Op. 10 No 9, Etude in F minor

No fingering in AI & A

Fingering in FE (→GE)

..

Chopin's fingering in bar 22, both in the R.H. and the L.H. was added in a proofreading of FE (→GE). In EE the fingering of the L.H. was added by Fontana (also in the next bars), what is more, he changed one of the digits given by Chopin.

category imprint: Differences between sources

issues: EE revisions , Authentic corrections of FE