Issues : Accidental below/above the note

b. 33-68

composition: Op. 63 No. 1, Mazurka in B major

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In AI the middle section of the Mazurka, bars 33-68, is written down – like the outer sections – in a key signature containing 5 sharps, and in order to write d and a notes, naturals put next to individual notes are applied. The notation is generally careful, and we indicate a few certainly overlooked naturals to A or a notes in the notes on bars 34, 38, 44 and 52 (see also bars 36 and 46).
Chopin committed more inaccuracies in the second part of this section (from bar 53), in the version prepared for print. 

category imprint: Differences between sources; Corrections & alterations

issues: Accidental below/above the note

b. 51

composition: Op. 63 No. 1, Mazurka in B major

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In the main text we add a cautionary  to b, as it was performed in GE3. The accidental is also in AI, perhaps by mistake, since it does not include the necessary  lowering a to a

category imprint: Differences between sources; Editorial revisions

issues: GE revisions , Cautionary accidentals , Omission of current key accidentals , Accidental below/above the note , Last key signature sign