The reasons for Johann Sebastian Bach’s attraction to the chorales of Martin Luther are many. Luther was not only the founder and guiding spirit of the Protestant Reformation, he was a poet of genius and, as a composer (or at least a melodist), remarkably imaginative, versatile, and effective. Apart from all liturgical and theological considerations, Bach, as a musician, was particularly fascinated by two types of melody writing that had been cultivated and indeed mastered by Luther. The first category consisted of melodies in the major mode. These tunes proceed to clear tonal goals, creating a sense of tonal direction and, more generally, conveying an almost palpable sense of purpose. In conjunction with their texts, they project an aura of sublimity or majesty. Bach was understandably attracted to the solid, sturdy, sharply profiled—”honest”—tunes of such melodies as those of Ein feste Burg and Vom Himmel hoch. He was able to capture what I like to think of as the “healthy,” affirmative attributes of these tunes in simple harmonizations. But they also inspired him to displays of contrapuntal artifice that clothe the folk-like tunes in something like the musical equivalent of the mantle of royalty, while they also represent a devoted and devout musician’s labor of homage. Perhaps, too, such grandiose designs were conceived as a reflection or symbol of the miraculous intricacy and order of God’s universe.

Consider the opening of Bach’s last church cantata, the final version of Ein feste Burg. Dating from the last decade of his life-the same period during which the composer produced a series of increasingly elaborate explorations of the complexities of canon and counterpoint, the Goldberg Variations, the Musical Offering, the Art of Fugue, the Canonic Variations on Vom Himmel Hoch —the opening chorus of Bach’s Reformation cantata is, technically considered, his most complex chorale chorus but also his most exhilarating. Without any instrumental introduction, the voices of the chorus enter at once singing the chorale text to melodic lines obviously derived from Luther’s tune in busy fugal imitation until the unembellished chorale melody itself, the cantus firmus, sounds from on high, in long notes, by the instrumental forces (by the oboes, and perhaps a choir of trumpets, as well) and is then thunderously answered, in strict canon, three octaves lower, by the instrumental basses and organ. The sense of heaven and earth opening wide and resounding with the glory of God never has been more vividly evoked.

But Martin Luther also was gifted at creating melodies that occupied the end of the stylistic and expressive spectrum opposite from that represented by Ein feste Burg and Vom Himmel hoch —and Bach was just as attracted to them. I am referring to melodies such as Aus tiefer Not schrei ich zu dir or Ach Gott vom Himmel sieh darein. Quite unlike the readily accessible, modern-sounding, major-mode melodies of the former, those of Aus tiefer Not and Ach Gott vom Himmel sound archaic, indeed exotic, even alien. They belong to the long-since obsolete church modes (obsolete even in Bach’s time), in particular the Phrygian mode, in which the second scale degree is only a half-step above the tonic pitch. When such melodies, like Luther’s, are well crafted—with sharply delineated contours and sensitive placement of the characteristic steps and intervals of the mode—they can be both memorable and deeply expressive.

The archaic idiom of hymn melodies of this sort frequently inspired Bach to adopt a self-consciously retrospective compositional style when setting them as cantata movements or even as organ chorales. In order to appreciate their unconventional treatment in his cantatas, let us first consider his more usual technique of chorale elaboration, as found, for example, in the opening chorus of the Advent cantata, Nun komm, der Heiden Heiland, BWV 62, composed for the First Sunday of Advent, 1724. The movement begins, in typical fashion for a chorale cantata of the 1724 cycle, with an orchestral introduction, in this instance with some intimations of the chorale tune in the instruments. After this introduction (or ritornello), the lower voices of the chorus enter in imitation with a version of the first line of the chorale that anticipates the formal entrance of the traditional melody, the cantus firmus, presented by the sopranos. Thereupon, a portion of the orchestral ritornello returns and prepares the way for the reappearance of the chorus and the soprano cantus firmus with the presentation of the next line of the chorale and so on, until the end. The movement concludes with a repetition of the original orchestral ritornello, as it appeared at the beginning. In sum: with its alternation of orchestral ritornelli and solo episodes—the solo episodes, this time, consisting of the lines of the chorale stanza—the movement follows the formal design of the contemporary, i.e., “modern,” Italian baroque concerto.

The style of the opening chorus of Aus tiefer Not schrei ich zu dir, BWV 38, stands in the starkest contrast to this normal procedure. It dispenses almost entirely with the brilliant color palette and lively motivic activity of the independent instrumental ensemble, as well as with the energetic rhythms and clarity of form that are the hallmarks of the Italian concerto—all of which were prominently displayed in Nun komm, der Heiden Heiland —in favor of an uncompromising, austere contrapuntal texture: a steady, almost ponderous, rhythmic tread, and no independent instrumental parts at all (except for the basso continua). The result is a compositional idiom reminiscent of Renaissance polyphony, specifically that associated with the sixteenth-century motet—a style of composition that would have been thoroughly familiar to Martin Luther.