ABSTRACT
Bach's St. John Passion comes down to us in two main sources: a score begun by the composer near the end of the 1730s but mostly copied a decade later by another scribe; and a set of parts documenting at least four different performances over a span of twenty-five years. 1 While the score presents a relatively smooth appearance, the parts confront the reader with a minefield of insertions, deletions, reworkings, and reinstatements, all carried out by an equally daunting variety of means: crossing out, writing in, cutting away, sewing over. No one attempting to steer a path through this terrain will likely venture forth without the guidance provided by Arthur Mendel's critical report to his edition of the Passion in the Neue BachAusgabe.2 Not that Mendel makes the going easy-to put it mildly. But he does seem to have gone everywhere first and virtually never to have put a foot wrong. In one instance, however, I have found it impossible to follow Mendel's lead.
