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b. 3

composition: Op. 24 No. 1, Mazurka in G minor

 A phrase mark in A

A tie in GE (→FEEE)

..

The slur of A clearly has a phrasing function and relates to whole chords, also the progression of the upper voice g1-a1. Relocating it to the side of the note heads, which was one of routine operations performed by engravers, completely changed the sense of that marking. 

category imprint: Differences between sources

issues: Placement of markings , Errors in GE

b. 3-4

composition: Op. 24 No. 1, Mazurka in G minor

A slur in  A (→GEFE)

No slur in EE

..

In EE, the upper slur in those bars was omitted, probably by mistake.

category imprint: Differences between sources

issues: Errors in EE

b. 3

composition: Op. 24 No. 1, Mazurka in G minor

..

In GE2 (→GE3) a cautionary  was added before a1 on the last chord. That unjustified revision was probably done to imitate Chopin's signs in analogous bars 11, 51 and 59.

category imprint: Differences between sources

issues: GE revisions , Cautionary accidentals

b. 3-4

composition: Op. 24 No. 1, Mazurka in G minor

..

Visible in A is the erased original version of the accompaniment, in which both bars had G crotchet with a staccato dot falling on the 1st beat. Both bars also had pedalling analogous to the pedalling preserved in adjoining bars. The notation before the change was as follows: 

category imprint: Corrections & alterations; Source & stylistic information

issues: Corrections in A , Accompaniment changes

b. 3

composition: Op. 24 No. 4, Mazurka in B♭ minor

..

A  heightening g1 to g1 is missing from all the sources. The use of g1 between f1 and g1 is so obvious in this context that the error went unnoticed for several dozen years.  

category imprint: Editorial revisions; Source & stylistic information

issues: Errors of A , Last key signature sign