JC
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In JC, there are no flats lowering a and a1 into a
and a1. The undeniable oversight of Chopin in [A] (→JC) is revealed by the cautionary 
before a in bar 7.
Compare the passage in the sources »
category imprint: Differences between sources
issues: Cautionary accidentals, Omission of current key accidentals, Errors of JC
notation: Pitch