The warning against false prophets elicits from the anonymous text writer of BWV 45 words of such orthodoxy that even the new Pope would be pleased. We are used to Bach’s complete engagement and profound identification with his texts. Our cantata is a remarkable but significant exception. One must quickly say that this cantata is neither a work of insincerity or even lack of interest. Rather the music of this very energetic and beautiful work seems to lead an independent, but cogent life of its own.The work opens with an unpromising quote from Micah. Micah, one of the twelve minor prophets, is best known as the predictor of the Messiah’s birth in Bethlehem. He was probably a contemporary of Isaiah but has none of the ringing brilliance of that astonishing figure. The pro forma, rather characterless words bring forth from Bach a fugal chorus of extraordinary energy and grandeur. While the text setting is perfectly, even scrupulously correct, the effect is that of a major top-drawer Bach instrumental piece. The tenor aria with its heavy first beat-oriented rhythm is a striking and minor-key equivalent.
One of the most impressive things about this cantata is its superb sense of proportion and balance; each movement is not only the perfect length in itself, but the sum total of the cantata has a complete and superb symmetry. The second part of the cantata begins with a quotation from Matthew; not the passage about false prophets that is the reading for this cantata, but Christ’s ferocious words to the hypocrites that are in the subsequent lines. Once again the crackling energy of the string parts and the bravura melismas of the bass are the most striking things. The juxtaposition of the words from Micah and Jesus’ fierceness is mysterious unless the texts are read together as exhortations to a society that has lost its energy and direction. Certainly the wonderful but odd alto aria supports this thesis, for the jaunty and high-profile flute theme is never taken up by the singer. The voice line is almost subsidiary to the dazzling trio sonata that is going on in the instruments. A very rich and beautiful harmonization of “O Gott, du frommer Gott” ends the cantata.