12. Both manuscripts are in the hand of Michel, Bach’s ubiquitous Hamburg copyist. All that this allows us to say is that the copies were made after 1768. See, for one, Rachel Wade, The Keyboard Concertos of Carl Philipp Emanuel Bach (Ann Arbor, 1979), 26. On the copies, see The Collected Works for Solo Keyboard, ed. Berg, IV: ix, xix, 103–123.