It was the battle-song of the Reformation, stirring men to valiant deeds; and it did equal service in sustaining and consoling the Reformers in their darkest hours. "Come, Philip, let us sing the Forty-sixth Psalm," was Luther's customary greeting to Melanchthon, when the gentler spirit quailed before approaching danger, or success seemed doubtful. In music it has frequently served an important purpose. Not only Bach, but other composers of his time arranged it. Mendelssohn uses it with powerful effect in his Reformation symphony. Nicolai employs it in his Fest overture. Meyerbeer more than once puts it in the mouth of Marcel the Huguenot, when dangers gather about his master, though the Huguenots were not Lutherans but Calvinists; and Wagner introduces it with overwhelming power in his triumphal Kaiser March. Bitter, in his Life of Bach, says:-- "The bicentenary Reformation Festival was celebrated in October and November, 1717, and at Weimar especially it was, as an old chronicle tells us, a great jubilee. Bach composed his cantata, 'Ein' feste Burg,' for the occasion. In this piece it is clear that he had passed through his first phase of development and reached a higher stage of perfection." Winterfeld is inclined to the same belief; but Spitta, in his exhaustive biography of Bach, argues that it must have been written either for the Reformation Festival of 1730, or for the two hundredth anniversary of Protestantism in Saxony, May 17, 1739. The former date would bring its composition a year after the completion of his great Passions music, and four years before his still more famous "Christmas Oratorio,"--a period when he was at the height of his productive power; which favors the argument of Spitta, that in 1717 a chorus like the opening one in the cantata was beyond his capacity.[9] In the year 1730 Bach wrote three Jubilee cantatas, rearranged from earlier works, and Spitta claims that it was only about this period that he resorted to this practice. Further, he adds that "the Chorale Chorus [the opening number], in its grand proportions and vigorous flow, is the natural and highest outcome of Bach's progressive development, and he never wrote anything more stupendous." The cantata has eight numbers, three choruses and five solos. The solo numbers are rearranged from an earlier cantata, "Alles was von Gott geboren" ("All that is of God's creation"), written for the third Sunday in Lent, March 15, 1716. The opening number is a colossal fugue based upon a variation on the old melody and set to the first verse of the Luther hymn. It is followed by a duet for soprano and bass, including the second verse of the hymn and an interpolated verse by Franck,[10] who prepared the text. The third and fourth numbers are a bass recitative and soprano aria, the words also by Franck, leading up to the second great chorale chorus set to the words of the third stanza of the hymn, "And were the world all devils o'er,"