I think September 12th 1723 was one of those mornings in Leipzig that Bach must have said, ‘guys, today, we’re really going to kick some ass.’
For the 16th Sunday after Trinity (today), Bach composed one of his most extraordinary cantatas, BWV95 Christus der is mein Leben, based on the miracle recounted in Luke of Jesus’ calling back to life the son of the widow of Nain. The entire cantata is beautiful and special for many reasons, but especially because it quotes not one, not two, but four different chorales, which together convey the message of how death in the Christian faith is the necessary and therefore joyful passage into the resurrection to eternal life.
But the first movement is a gem in itself, because it uses two (!) chorales — Christus der ist mein Leben and the well-known Mit Fried und Freud ich fahr dahin — which develop this theme, and which are separated by a tenor recitative which links them both thematically and musically. As if this is not enough, Bach pulls out all the stops as regards text illustration (fermatas, dissonances and silences in all the right places, for instance), tempo and metre changes, instrumental colours (the corno da tirarsi — no-one really is sure what it was, but given the part written for it, it must have been a brilliant and versatile instrument requiring a ditto player) and also asking the oboe players to switch instruments mid-movement, using all his contrapuntal dexterity to bring his point across…
There is so much more to say, also about the rest of the piece, but for now: have fun!
(Okay, just one more detail: at the very end of the opening movement, in the final chord, Bach lets the corno quote the first line of the Mit Fried und Freud fahr ich dahin chorale once more. How cool is that!)