ABSTRACT
As a composer Carl Philipp Emanuel Bach was restless in the sense that he frequently revised his works. His revisions run the gamut from changing one note to recasting entire movements or substituting one aria for another within a large-scale vocal work. When Bach did revise on musical grounds, he of course occasionally did so because what he had written contained an obvious mistake, but in general he revised out of consideration for the overall structure of a work. Bach underscored the ends of each verse within his through-composed choral arrangement by assigning the last four bars of each verse to the four vocal parts, a capella. The change shows Bach's habit of revision at crucial points in the structure of a work, such as the imminent return of the primary theme. When a revision deviates from Bach's normal type, one should suspect that the revision is due to practical considerations or outside influences, rather than Bach's innate restelessness.
