Op. 2, Variations in B♭ major
Op. 10, 12 Etudes
Op. 11, Concerto in E minor
Op. 21, Concerto in F minor
Op. 22, Polonaise in E♭ major
Op. 24, 4 Mazurkas
Op. 25, 12 Etudes
Op. 26, 2 Polonaises
Op. 27, 2 Nocturnes
Op. 28, 24 Preludes
Op. 30, 4 Mazurkas
Op. 35, Sonata in B♭ minor
Op. 50, 3 Mazurkas
Op. 63, 3 Mazurkas
Op. 64, 3 Waltzes
Op. 2, Variations, complete
The sources do not include an accidental over the mordent. In this harmonic context, the use of b
is obvious, hence in the main text we add a 
over the ornament. Chopin hardly ever put accidentals over trills or mordents in such situations, generally leaving the task of finding the right sound of the auxiliary note to the performer's imagination.
Compare the passage in the sources »
category imprint: Interpretations within context; Editorial revisions
issues: Omissions to cancel alteration, Inaccuracies in A
notation: Ornaments
