90 The date actually was November 1720. At Cöthen Bach had an inferior Organ and little scope for his attainments; his chief duties were in connection with the Prince’s band. The yearning to get back to the Organ, which eventually took him to Leipzig in 1723, shows itself in his readiness to entertain an invitation to Hamburg in 1720. 91 Three Organ movements by Bach upon Wolfgang Dachstein’s melody, _An Wasserflüssen Babylon,_ are extant. See notes upon them and their relation to the Hamburg extemporisation in Terry, _Bach’s Chorals,_ Part III. 92 As at Halle in 1713, Bach does not appear to have gone to Hamburg specially to compete for the post of Organist to the Church of St. James, vacant by the death of Heinrich Friese in September 1720. He was not able to stay to take part in the final tests, nor was he asked to submit to them, since his visit to Hamburg had given him an opportunity to display his gifts. In the result the post was given to Johann Joachim Heitmann, who acknowledged his appointment by forthwith paying 4000 marks to the treasury of the Church. See Spitta, ii. 17 ff. 93 Johann Kuhnau died on June 25, 1722. 94 On the title-pages of his published works Bach describes himself as “Capellm. und Direct. Chor. Mus. Lips.” 95 Forkel has practically nothing to say regarding the Leipzig period of Bach’s musical life. That a professed historian of music, setting before the public for the first time the life of one whom he so greatly extolled, and with every inducement to present as complete a picture of him as was possible, should have taken no trouble to carry his investigations beyond the point C. P. E. Bach and Agricola had reached in the _Nekrolog_ of 1754 is almost incredible. The only reason that can be adduced, apart from the lack of a really scientific impulse, is that Forkel was almost entirely ignorant of the flood of concerted church music which poured from Leipzig from 1723 to 1744. His criticism of Bach as a composer is restricted practically to Bach’s Organ and Clavier works. 96 On November 19, 1728. Latterly his interest in music had waned. The fact, along with Bach’s concern for the education of his sons and his desire to return to the Organ, explains his abandonment of the more dignified Cöthen appointment. 97 The score of this work was in Forkel’s possession, but was missing from his library in 1818 and was assumed to be lost until, in 1873, Rust was able to show that Bach used for the occasion certain choruses and Arias from the _St. Matthew Passion,_ which he was then writing, with the first chorus of the _Trauer-Ode_ as an opening of the extemporised work. See Spitta, ii. 618; Schweitzer, ii. 208.