Op. 50 No. 1, Mazurka in G major

Autograph fair-score comprising the entire opus 50, without a separate title page – title, dedication, three publishers and opus number* were written by Chopin over the text of the first Mazurka. The additions performed in pencil visible in A1 (mainly even numbers) come from the engraver and mark the division of the text into great staves and pages implemented in FE1.

A1 of this Mazurka was generally written in a careful manner; however, the interpretation of slurs poses a number of difficulties, e.g. in b. 2-3 or 27-28. It also contains a significant number of corrections (crossings-out), including 5 major ones, as a result of which the changed text had to be entered on an adjacent stave – in b. 41-42, 74, 76, 85 and 101 – and over 40 minor ones. The groups of the R.H. part corrections in b. 41-47, 92-97 and the corrections in b. 101-102 prove that elements of the Mazurka's texture and harmony were still being improved. The refining process continued in later sources – see descriptions of FE1, GE1 and FE2.

Bars 2-16 are provided with numbers from 1 to 15; that numbering system was then used to mark b. 58-72 in an abridged manner.

The more pronounced mistakes and inaccuracies of notation include:

• the missing R.H. slur in b. 3-4,
• the missing tie of g in b. 21-22,
• the missing  lowering e¹ to e¹ in b. 45.

^* Next to the opus number, Chopin added a note to the publisher in the side margin: 'I am not certain of the opus number, would you mind checking the number of the last one?' [original version in French: 'je ne suis pas sûr le numero (!) d'euvre (!), – ayez la bonté de voir le numero (!) du dernier'].