-The second part of our look into Cantata 78, where we look at the opening chorus.
For an overview of this cantata and a deeper look at the wonderful duet and the rest of the parts, see the episode previous.
For this lamentation hymn about Christ's anguish used as ransom for our salvation, Bach chose to accompany the tune with a "lament bass." To start, he sets up this sad descending bass line as a repeated pattern under a varying texture (passacaglia). The stress on beat 2 of 3 is a Sarabande metric figure, reminding us of his more famous passacaglia "Crucifixus" in the B Minor Mass.
When voices enter, the tortured chromaticism is imitated and they herald the coming of the soprano melody, which would have been recognized by the churchgoers on that Sunday in 1724. Variations in musical texture always match the line of text currently being sung. In the many variations, the lamenting line can be in any instrument or voice, and may also be inverted and ascend in a sort of wailing prayer.