It is unclear how the difference between the variants of FE (→EE1→EE2) and GE occurred – there are no visible traces of corrections in both sources. Due to stylistic reasons, a possibility that Chopin replaced b2 present in FE with a
2 seems to be less likely. The introduction of a2 mitigates – in the climax of the progression – both the melodic tension (fifth instead of sixth) and harmonic one (abandonment of dissonance). In turn, the reviser of EE3 undoubtedly wanted to change the note to a2, yet the engraver overlooked the 
raising a2.
Compare the passage in the sources»
category imprint: Interpretations within context; Differences between sources
issues: EE revisions
notation: Pitch