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b. 138

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

..

In A (→GE), there is a  entered before d flat1 in the 1st chord. That sign, totally unnecessary in the context, was removed in the proofing of FE (→EE), perhaps at Chopin's request. It is conceivable that the much more clearly written  lowering f1 to f flat1 in A was, in Chopin's intention, to replace the sign put mistakenly before d flat1.

category imprint: Differences between sources

issues: Cautionary accidentals , Authentic corrections of FE

b. 144

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

..

In A (→GE1FE) there are no naturals raising d flat-d flat1 to d-d1. This obvious omission on the part of Chopin was corrected in EE and GE2 (→GE3).

category imprint: Differences between sources

issues: Omission of current key accidentals , Errors of A