Further, in comparing the sixth measure of this Christe with the tenth part of the Canzona of Bach, we see why these two themes, although quite in the style of Bach, still are obviously the result of his study of Frescobaldi; in fact, this measure contains a fragment of the theme just quoted, with the very alteration afterwards made by Bach.
In this present case of the employment of a chromatic countersubject Bach evidently had Frescobaldi in mind; considering, and rightly, the frequent use of motives of this kind to be characteristic of the latter. But while Bach believed himself in so far indebted to an Italian master, he was in reality only following the traditions of Sweelinck,[88] who had already furnished him noteworthy examples of this style.
In fact, Frescobaldi acquired these resources during his stay in Flanders; perhaps he obtained them from Sweelinck himself, whom he undoubtedly knew in Amsterdam. A Fantasie by Sweelinck, edited by R. Eitner,[89] is written wholly upon this form of the Ionic tetrachord:
We may compare the counterpoint which accompanies it with those of Frescobaldi and of Bach:
