51. For a thorough compilation of the evidence bearing on Beethoven’s evolution as a keyboard player, see Th[eodor] von Frimmel, “Der Klavierspieler Beethoven,” in Beethoven-Studien, II: Bausteine zu einer Lebensgeschichte des Meisters (Munich and Leipzig: Georg Müller, 1906), 201–271. “Without risk,” writes Frimmel (211) “we can assume that it was chiefly the principles of C. Ph. E. Bach’s keyboard playing according to which Neefe instructed the young Beethoven.” (The emphasis is Frimmel’s.)