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. 76

composition: (Op. 4), Sonata in C minor, Mvt II

No slurs in A & EE1

Slurs in GE (→FE,IE) & EE2

..

The slurs added in GE (→FE,IE) after analogous bar 74 can be considered justified. However, as the presence or absence of these slurs is only one of a few differences between bars 73-74 and 75-76 present in A, in the main text we do not include this addition.
The absence of the slurs in EE1 is almost certainly an oversight, corrected in EE2.

category imprint: Differences between sources

issues: EE revisions , Errors in EE , GE revisions

b. 77

composition: (Op. 4), Sonata in C minor, Mvt II

..

In A the L.H. part is written in shorthand – only top octave notes and the con 8va - - indication. In the editions it was written in full.

category imprint: Differences between sources

issues: GE revisions , Abbreviated octaves' notation

b. 77

composition: (Op. 4), Sonata in C minor, Mvt II

No mark in A, EE & IE

Staccato dot in GE (→FE)

..

The staccato dot added in GE (→FE) is an arbitrary decision of the engraver or a mistake. Two similar sequences in the R.H. part (bar 73 and 75), in which it is also the first, longer octave that is devoid of a dot, prove that it was also in this case that Chopin did not write this mark on purpose. The compliance of EE and IE with the A version can be explained by revisions aimed at standardising this bar after bar 73 and 75. 

category imprint: Differences between sources

issues: EE revisions , GE revisions ,

b. 77

composition: (Op. 4), Sonata in C minor, Mvt II

stacc. in sources

staccato suggested by the editors

..

In the main text we write the stacc. abbreviation (present in the sources but rarely used) in full.

category imprint: Editorial revisions

b. 78

composition: (Op. 4), Sonata in C minor, Mvt II

f2 on 2nd & 3rd beat in sources

f2 only on 2nd beat, our alternative suggestion

..

The f2 minim played on the 2nd beat of the bar, followed by a crotchet at the same pitch, suggests a possible mistake – the note was either supposed to be a crotchet or it is the repeated f2 note on the 3rd beat that is a mistake. It could have been, e.g. an unfinished correction, in which Chopin added a new version without removing the previous one. As the change of value from a minim to a crotchet can only influence the performance manner of this note, we do not provide the version with a crotchet as a separate variant. In the main text we keep the original notation; it is true that it is puzzling, but it does not include a clear mistake.

category imprint: Source & stylistic information

issues: Errors of A