A more accurate specification of the unexpected B7 chord in the solo part already at the beginning of the bar must be a Chopinesque improvement introduced in the proofreading of FE (→EE). It is already a second change in this bar with respect to the earliest preserved version, after the rhythmic diversification – see the adjacent note.
Compare the passage in the sources »
category imprint: Differences between sources
issues: Accompaniment changes, Authentic corrections of FE
notation: Articulation, Accents, Hairpins