158 Schweitzer advances the opinion, which may perhaps be challenged, that inevitable and natural as Bach’s melodies are, they do not give the impression of “effortless invention.” Bach, he holds, worked like a mathematician, who sees the whole of a problem at once, and has only to realise it in definite values. Hence, he agrees with Spitta, Bach’s way of working was quite different from Beethoven’s. With Beethoven the work developed by means of episodes that are independent of the theme. With Bach everything springs with mathematical certainty from the theme itself. See Schweitzer (i. 211) on Bach’s methods of working. 159 Johann Sebastian Bach’s _Vierstimmige Choralgesänge_ were published in 1765 and 1769. C. P. E. Bach was concerned only with the first volume. Forkel perhaps refers to an edition of the _Choralgesänge _ issued by Breitkopf in four parts at Leipzig in 1784, 1785, 1786, and 1787, and edited by C. P. E. Bach. 160 Forkel indicates the period 1720-1750. But in 1720 Bach had already completed the _Orgelbüchlein_ and the greater part of his Organ works. 161 * There are people who conclude that Bach merely perfected harmony. But if we realise what harmony is, a means to extend and emphasise musical expression, we cannot imagine it apart from melody. And when, as in Bach’s case, harmony is actually an association of melodies, such a view becomes the more ridiculous. It might perhaps be reasonable to say of a composer that his influence was restricted to the sphere of melody, because we may get melody without harmony. But there cannot be real harmony without melody. Hence the composer who has perfected harmony has influenced the whole, whereas the melodist has left his mark only on a fraction of his art. 162 As has been pointed out already (supra, p. 14) Bach’s earliest church Cantatas date from the Arnstadt period. 163 The statement certainly needs a caveat. No composer of his period studied his text more closely or reverently than Bach. No one, on the other hand, was more readily fired by a particular word or image in his text to give it sometimes irrelevant expression. 164 Of Bach’s church Cantatas 206 have survived. In only 22 of them does Bach fail to introduce movements based upon the Lutheran Chorals. 165 We must attribute to Forkel’s general ignorance of Bach’s concerted church music his failure to comment upon a much more remarkable feature of the recitatives, namely, their unique treatment of the human voice as a declamatory medium, a development as remarkable as Wagner’s innovations in operatic form a century later.