166 It was not the imperfections of the choir but the indifference of Bach’s successors at St. Thomas’, Leipzig, that was chiefly responsible for the neglect of his Cantatas in the latter half of the eighteenth century. Johann Friedrich Doles (1716-89) was the only Cantor who realised the greatness of his predecessor’s concerted church music. 167 The _Trauer-Ode_ was performed on October 17, 1727. Bach finished the score two days before the performance! A parallel case is that of Mozart, who finished the overture of _Don Giovanni_ on the morning of the first performance of the Opera, and actually played it unrehearsed that evening. 168 It has been pointed out already that Bach used the _St. Matthew Passion_ music, set to other words, for the occasion. No. 26 (“I would beside my Lord be watching”) was sung to the words “Go, Leopold, to thy rest”! 169 Of the 206 surviving Cantatas, 172 were written for the Leipzig choir. 170 Forkel’s knowledge is very incomplete. 171 Elsewhere Forkel mentions only one of the secular Cantatas. 172 There is a tradition that Bach wrote a comic song, _Ihr Schönen, höret an,_ which was widely current about the time of his death (Spitta, iii. 181 n.). The Aria, _So oft ich meine Tabakspfeife,_ in A. M. Bach’s _Notenbuch_ of 1725, should be mentioned. See B. G. xxxix. sec. 4. 173 Bach’s method has come down to us in treatises by two of his pupils, C. P. E. Bach’s _Essay_ and Kirnberger’s _Die Kunst des reinen Satzes in der Musik,_ to which reference has been made already. 174 Supra, p. 60. 175 Bach wrote eighteen Preludes for Beginners. They are all in P. bk. 200. 176 Most of these movements, which Bach called indifferently “Inventions” (ideas) and “Praeambula” (Preludes), were written in 1723. They are in P. bk. 201. 177 Heinrich Nikolaus Gerber, who was Bach’s pupil from 1724 to 1727, particularly emphasises this feature of Bach’s teaching. 178 See on the whole matter Spitta, iii. 117 ff. Bach’s method is illustrated by his _Rules and Instructions_ (1738) printed by Spitta, iii. 315 ff., and also by the _Einige höchst nöthinge Regeln_ at the end of A. M. Bach’s _Notenbuch_ (1725).