28. The manuscript is at Cracow, Biblioteka Jagiellónska, Mus. ms. Bach P 771. I am deeply grateful to Darrell Berg for sharing copies. A description of the manuscript sources for this sonata in its two versions is given in Carl Philipp Emanuel Bach Edition, series I, vol. 24, Keyboard Sonatas, ed. Claudia Widgery (Oxford: Oxford University Press, 1989), 106. For a better understanding of the new finale and its dating, see Pamela Fox, “Toward a Comprehensive C. P. E. Bach Chronology: Schrift-Chronologie and the Issue of Bach’s ‘Late Hand’,” in Carl Philipp Emanuel Bach: Musik für Europa. Bericht über das Internationale Symposium, ed. Hans-Günter Ottenberg (Frankfurt an der Oder: Konzerthalle “Carl Philipp Emanuel Bach,” 1998), 317–319.