Authorities are divided on the dating of BWV 34 ("O eternal flame, o fount of love"), most opting for the early 1740s, although it as been ascribed to as late as ca. 1746. Ostensibly this makes this cantata for Whit Sunday one of the last of Bach's sacred cantatas, but with the exception of two recitatives the material goes back to a wedding cantata of the same name composed in 1726 for a Leipzig clergyman. The suitability of a parody adapted to Whitsuntide is evident from the first part of the title, which bears a close relationship to the "tongues of fire" spoken of in the words of the Epistle for Whit Sunday. They obviously served as a point of departure for Bach's anonymous poet, who fashioned a new text based not on the Epistle but on the day's Gospel (John 14: 23-31), which concentrates on the blessings God bestows on those who love him. The lavish scoring includes three trumpets, timpani, two flutes, two oboes, strings and continuo bass, the forces (excepting the flutes, who would have doubled on oboes) employed in the resplendent opening and closing choruses. The opening da capo chorus in particular is colorfully dramatic, the rapid figuration in the first violins evoking the flickering of flames, and the composer introducing vivid examples of word painting. A brief declamatory recitative for tenor ("Lord! Truth and Right") leads to the only aria in the cantata, a wonderfully tender, but ardent, outpouring for alto extolling the merits of those "whom God has chosen." The accompaniment of two flutes and muted strings emphasizes the reticent fervor of the aria. The cantata concludes with a noble recitative for the bass, and a final chorus in two parts giving thanks for the peace of God. After the composer's death, the score passed through the hands of his eldest son, Wilhelm Friedemann, into the possession of the Duchess of Saxe-Weimar. It is now housed in the Staatsbibliothek, Berlin. ~ Brian Robins, All Music Guide
