At the end of cantata BWV 120 in Bach’s manuscript we find the inscription ‘In Fine Intrada con Trombe / e Tamburi’ clearly in Bach’s own hand. While we cannot reconstruct the original music that Bach intended, perhaps this indicates an instrumental piece with trumpets and drums should be inserted at this point? It is due to this small instruction by Bach, coupled with the Celebration of St. Michael and All Angels, that we append the one movement fragment Nun ist das Heil und die Kraft, BWV 50.
One only has to think of the ‘Sanctus’ in the B minor Mass to realize that Bach embraced and relished the musical imagery of Book of Revelation and the concept of the angelic hosts. A stunning collection of cantatas composed to honor the archangel Michael has survived from the most productive years of Bach’s cantata composition, the 1720s.
Michael the archangel (the name means ‘Who is like God?’) is one of the few figures to appear in the Old and New Testaments, the Apocrypha and the Koran. When Lucifer, highest of the Seraphim, led a mutiny against God, he became transmogrified into the Devil, appearing either as a serpent or a ten-headed dragon; Michael, at the head of God’s army in the great eschatological battle against the forces of darkness, was the key figure in his rout.
In BWV 50, Nun ist das Heil und die Kraft, Bach quotes the last of the above paraphrased verses from Revelations 12 and makes it his text for one of his most impressive works. In a compact movement of less than four minutes, Bach draws on two vocal and three instrumental choirs (of trumpets, oboes and strings) to encapsulate the victory celebrations of the forces of Light through use of a permutation fugue in which there are no episodes, only subjects and countersubjects that can be rearranged in various orders. The musical complexities are enhanced by the special effect of one whole choir pitted against the rest. Musicologist Klaus Stein explains these features as products of Bach’s imaginative response to the text, the words from Revelation being spoken by a ‘loud voice... in Heaven’ and Bach returning them from earth in echoing assent.