Op. 63 No. 1, Mazurka in B major

FE2 was corrected by Chopin, who introduced i. a. the following changes:

• corrected the erroneous last semiquaver in bar 7 from c¹-d¹ to b-c¹,
• moved  from beat 1 to beat 2 in bars 40 and 50,
• added  in bar 43,
• added four-bar slurs in bars 53-56 and 57-60,
• added long slurs in bars 53-58,
• added the overlooked sharps rising d to d in bars 59-60 and 62 and a to a in bar 60,
• lengthened the note f¹ in bars 65-67,
• extended the sound of f in bar 73, linking this quaver with the crotchet F by adding a stem,
• enriched the accompaniment by adding crotchets on the 3rd beat of bars 75 and 81,
• added a g¹ grace note to the crotchet on the 2nd beat of bar 86.

Some changes may have been the work of a reviser:

• adding overlooked ties to c¹ in bars 61-64,
• removing unnecessary sharps before a¹ in bars 83 and 85.

Despite detailed proofreading, a number of faults listed in characteristic of FE1 have not been corrected, the most serious of which are:

• misleading location of mordents under the R.H. thirds in bars 5, 7 and analogous,
• no sharps over mordents in bars 7, 15 and 75,
• overlooked  rising d to d in bar 63,
• Terzverschreibung error in bar 72.

Moreover, in bar 86 the semiquaver g¹ was changed to a¹, which may be a mistake made when adding a grace note before the next note.

Dating – Chopin's proofreading indicates that the two impressions of FE were released in a short interval. As FE1 was launched in November 1847, it can be assumed that FE2 was published in December, at the earliest. On the other hand, the cover of the copy of FE2 deposited at the Parisian Bibliothèque Nationale in February 1848 already includes a supplemented name of the London publisher, and there are also copies with an earlier version of the cover.* It allows us to assess that FE2 must have been ready in January 1848, at the latest.

^* Information after the Annotated Catalogue Online.