230 The work appeared in 1739. It was intended to contain works for the Organ only; the four Duetti are incongruous and seem to have crept in by mistake. See the scheme of the work discussed in Terry, _Bach’s Chorals,_ Part III. The Choral Preludes are in Novello’s ed., bk. xvi. 231 The work was published circ. 1747-50. Five of the six movements certainly, and the sixth with practical certainty, are adaptations to the Organ of movements out of Bach’s Church Cantatas. See Parry, _Bach,_ p. 535. The Chorals are in Novello’s ed., bk. xvi. 232 See supra, p. 65. 233 Thus the pedal sounds above the part given to the second manual and is often the topmost part. See Novello’s ed., bk. xvi. 4. 234 Published circ. 1742; the so-called “Goldberg Variations.” They are in P. bk. 209. 235 Variation No. 10 is a Fughetta in four parts. 236 Ten of the Variations are marked “a 2 Clav.,” that is, for two keyboards or manuals: Nos. 8, 11, 13, 14, 17, 20, 23, 25, 26, 28. Nos. 5, 7, 29 are marked “a 1 ovvero 2 Clav.” 237 The movement is constructed upon two merry folk-songs, _Kraut and Rüben haben mich vertrieben,_ and _Ich bin so lang nicht bei dir gewirt_. 238 See supra, p. 101. 239 In fact Bach wrote the early _Aria variata alla maniera Italiana_ (Peters bk. 215, p. 12) for the Clavier. For the Organ he wrote four sets of Variations upon as many Choral melodies (Novello bk. xix.). But all except the Goldberg Variations are youthful works, and in his maturity Bach clearly had no liking for the form. The theme of the Goldberg Variations, moreover, is itself a youthful idea; at least it dates back to as early as 1725, and is found in A. M. Bach’s _Notenbuch_ (No. 26, Aria in G major). 240 There is no reference to these corrigenda in the B. G. edition. 241 The work has been referred to already in connection with Bach’s membership of Mizler’s Society (supra, p. 112). It was composed presumably circ. 1746 and in point of technical skill is the most brilliant of Bach’s instrumental works. Forkel states that it was engraved after June 1747, when Bach joined Mizler’s Society. Spitta (iii. 295) is of opinion that it was already engraved by then. It is in bk. xix. of Novello’s edition. 242 Supra, p. 25.