Select: 
Category
All
Graphic ambiguousness
Interpretations within context
Differences between sources
Editorial revisions
Corrections & alterations
Source & stylistic information
Notation
All
Pitch
Rhythm
Slurs
Articulation, Accents, Hairpins
Verbal indications
Pedalling
Fingering
Ornaments
Shorthand & other
Importance
All
Important
Main


b. 34

composition: Op. 10 No 12, Etude in C minor

Octave in A

Chord in FE (→GE,EE

..

The octave in A is the original version, changed by Chopin in a proofreading of FE (→GE,EE). In FE the correction was inaccurately performed – there are no dots extending the added notes, while the  (cautionary) was placed at the pitch of b2. The rhythmic error was corrected in GE and EE and the  was moved before a2 in GE1, yet removed in EE and subsequent GE,s. 

category imprint: Differences between sources; Corrections & alterations

issues: EE revisions , Errors in FE , GE revisions , Cautionary accidentals , Rhythmic errors , Authentic corrections of FE

b. 34

composition: Op. 10 No 12, Etude in C minor

..

In A the accidentals are before each note of the chord at the beginning of the bar. In FE (→GE1,EE) the  before awas omitted. The accidental was added in GE2 (→GE3GE4).

category imprint: Differences between sources

issues: Inaccuracies in FE , GE revisions , Cautionary accidentals

b. 35

composition: Op. 10 No 12, Etude in C minor

..

In A there are no flats on the 2nd beat in the bar, which is certainly a mistake (cf. two previous bars). Both necessary accidentals were added in a proofreading of FE (→GE,EE).

category imprint: Interpretations within context; Differences between sources

issues: Omissions to cancel alteration , Omission of current key accidentals , Authentic corrections of FE

b. 37-39

composition: Op. 10 No 12, Etude in C minor

No fingering in A

Fingering in FE (→GE

Fingering in EE

..

In the main text we give the fingering added by Chopin in a proofreading of FE (→GE). In EE Fontana completed it with digits which naturally stem from Chopin's indications.

category imprint: Differences between sources

issues: EE revisions , Authentic corrections of FE

b. 37

composition: Op. 10 No 12, Etude in C minor

in A

in FE (→EE)

in GE

..

 in FE (→EE) instead of  in A is most probably a result of the engraver's error. In the entire Op. 10 a similar mistake was committed on a number of occasions (in the Etudes in A minor, No. 2, bar 12, E major, No. 3, bar 54, C minor, No. 4, bars 1, 8, 16, 26, 54, E minor, No. 6, bars 21 and 32). On the other hand, the origin of  in GE is unclear, although the presence of this mark in this place is possibly a mistake too.  

category imprint: Differences between sources

issues: Inaccuracies in FE , GE revisions