The Third Part of the _Clavierübung_ contains twenty-one arrangements of chorales.[143] The "Hymns of the Catechism" and the Creed furnish twelve of them, each melody treated twice, with or without pedal. These chorales may be cited as examples of certain well-defined types; it is unnecessary to identify each one of them separately, rather will we leave to the reader the task of such a classification. Some of them, however, are deserving of special mention; the _Vater unser im Himmelreich_ (treated in canon), for its extended proportions, for the fulness of its harmony; the _Aus tiefer Noth_ (_de Profundis_) in six parts, with double pedal, noteworthy in that it appears to have been written for two pedal-keyboards of different intensity, the melody dominating by its power, crying out amidst the symbolical chaos of this gigantic polyphony. [Footnote 143: P. vi, and vii. B.-G. iii.] We shall not again touch on that faculty which Bach possessed of translating into music the words of the chorales, whether in their most obscure meaning, or in their most obviously picturesque significance. _Ein' feste Burg ist unser Gott_, "A mighty fortress is our God," sings Luther, and Bach emphasizes the suggestion of impregnability by supporting the melody upon the deepest basses of the organ; but this firmness reveals itself only after the repulse of an attack, after the warring of the counterpoints below the ramparts. It is the same procedure as in the Reformation Cantata _Und wenn die Welt voll Teufel wär'_, "And were the world of devils full," as Luther's song runs; "on a sudden, figures of infernal aspect, issuing from unknown depths, rush to the assault upon the noble melody of the chorale."[144] [Footnote 144: Cart. _Un maître deux fois centenaire._] But such agencies partake rather of an instrumental style, interesting in an organ prelude, where they are more in place; in the cantata these counterpoints are entrusted to a bass voice; while putting the singer out of breath, they impress upon the audience a sort of wearisome anxiety; "without doubt," says Hanslick, "Bach obeys a fine symbolic instinct in entrusting the calm and steadfast melody of the chorale to one voice, while the other, in elaborate design, creeps about it; but not everything of symbolic significance must, for that reason, be beautiful in itself." It is known that the last work of Bach was a chorale-prelude upon the melody of _Wenn wir in höchsten Nöthen sein_, or _Vor deinen Thron trete ich_,[145] which he dictated upon his deathbed to his son-in-law, Altnikol. This composition was added to the plates of _Die Kunst der Fuge_ (the Art of Fugue), unfortunately lost, which Bach had had prepared at the time. [Footnote 145: P. vii, 58. B.-G. xxv.]