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b. 1-4

composition: Op. 28 No. 8, Prelude in F♯ minor

..

In the figurations featuring the interval of an octave, Chopin would often be satisfied with an accidental placed only next to the first note constituting that interval (cf., e.g. the Etude in A Major, Op. 10 No. 10, b. 5-8 or the Ballade in F Major, Op. 38, b. 48). In the Prelude in F Minor, such an extended validity of accidentals is a strictly observed rule – accidentals are absent even in the places where they are necessary to cancel the previous alteration (e.g. on the 2nd demisemiquaver on the 3rd beat of b. 4), while in b. 8 Chopin actually crossed out the necessary accidental next to the 2nd demisemiquaver in the 3rd figure. In the discussed bars, apart from the situation in b. 4 mentioned above, the problem concerns the 8th demisemiquaver in the 3rd group in b. 1-2 and 4, the 8th demisemiquaver in the 1st, 2nd and 4th groups in b. 3 and the 2nd demisemiquaver on the 3rd beat of b. 3. Such a notation is to be found in A (→FC,FEEE1), whereas EE2, GE1 and GE2 added the majority of the necessary accidentals (5, 6 and 7 out of the eight necessary, respectively).
The L.H. quavers falling an octave lower than the first semiquaver of a given figure provided with an accidental are written down in a similar way, without the necessary accidentals – see b. 3-4.  

category imprint: Interpretations within context; Differences between sources

issues: EE revisions , Accidentals in different octaves , GE revisions , Inaccuracies in A , Errors repeated in GE , Errors repeated in FE , Errors repeated in EE

b. 1-2

composition: Op. 28 No. 8, Prelude in F♯ minor

Long accents in A (→FC), contextual interpretation

4 short accents in FE

No marks in GE 

3 vertical accents in EE

..

The long accents written in A (→FC) were not reproduced correctly in any of the editions. Both the shorter marks in FE and their omission in GE could have been related to a very dense and not always rational vertical text layout. The change of the accents' font in EE is a revision, typical of that edition, while the omission of the third mark – an oversight.
In the main text we also include – unlike FE – the accents in b. 2, marked in the manuscripts as a repetition of b. 1. This issue is generally ambiguous, e.g. tempo/character indications are certainly not to be repeated, but slurs and pedalling marks continued in the next bars should definitely be repeated. In the case of accents, both possibilities are actually equivalent in this context – the marks are given here as a pattern and should be applied also in the next bars, hence the number of explicitly given accents (4 or 8) is insignificant (cf., e.g. the accents at the beginning of the Prelude No. 6 in B Minor or the Etude in C Major, Op. 10 No. 1). 

category imprint: Interpretations within context; Differences between sources

issues: Long accents , EE revisions , Inaccuracies in FE , Errors in EE , Errors in GE

b. 1

composition: Op. 28 No. 8, Prelude in F♯ minor

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EE added a poorly justified cautionary  before a2, probably by analogy with b. 5. In A one can see that Chopin initially wrote that accidental, whereupon he considered it superfluous and crossed it out.

category imprint: Differences between sources; Corrections & alterations; Source & stylistic information

issues: EE revisions , Deletions in A

b. 1-2

composition: Op. 28 No. 8, Prelude in F♯ minor

..

FE erroneously gives d instead of c as the last L.H. quaver in each of these bars. The errors, caused probably by this note in bar 1 being written somewhat imprecisely in A (bar 2 is marked as a repetition of bar 1 in the manuscripts), were corrected in FE2 (→EE).

category imprint: Interpretations within context; Differences between sources

issues: Errors in FE , FE revisions

b. 2

composition: Op. 28 No. 8, Prelude in F♯ minor

..

In A (→FC) b. 2 is marked with / signs as a repetition of b. 1. This raises doubts about whether and which performance indications are to be included in b. 2 (except for the tempo/character marking, of course) – FE (→EE) repeated pedalling markings and slurs, but omitted accents.

category imprint: Differences between sources

issues: Abbreviated notation of A