Pieces such as the Adagio and Fugue in C minor, K. 546, raise similar issues, since the original manuscript to the Adagio is lost, and the Fugue appears in Mozart’s output as a piece of juvenilia arranged for two pianos (K. 426). Originally published together as his 27th string quartet, this Adagio and Fugue fits the hands and feet of an organist well enough to raise the theory that it might have been originally composed on the organ. In the 1960s, a German minister named Johannes Pröger (1917-1992) recorded the work for organ in a version later published with him accredited only as an “editor,” which is the version Miller is playing from here.