Ein' feste Burg ist unser Gott

Nobody knew better than J.S. Bach how to take a sturdy chorale melody and turn it into contrapuntal gold. And nowhere does the gold gleam more brightly than in the opening chorus of Cantata BWV 80 “Ein feste Burg ist unser Gott”—a towering late addition to a cantata Bach reworked when it was repurposed to celebrate Reformation Day—scored for four-part chorus, four vocal soloists, and instrumental forces adding three types of oboe to strings and continuo. Luther’s great chorale Ein feste Burg ist unser Gott (A mighty fortress is our God) bookends the work, first revealed as a blazing chorale-fantasia that erupts without an instrumental curtain-up, and carries all before it on a tide of deftly worked jubilation. The bass soloist is given a vigorous vocal workout in the duet that follows, while solo soprano superimposes the chorale by way of descant. And striking, too, is the central appearance of the chorale, punched out by the choir in octave unison while the strings spin a fizzing accompaniment. After such highly seasoned fare, the hymn’s final appearance is as a straightforward harmonisation for choir and orchestra; an unvarnished assertion of faith.