I was cleaning felt out of a hammer rail this morning and thinking about the band call for this one: three trumpets and timpani, for a war in heaven, Leipzig 1726. It's a Thursday gig, Michaelmas, the trade fair opening in the same town — that engraving of the square with the cart and the fountain, imagine it full. Listen for the drums under the opening chorus. Somebody sat up copying those parts out.
The trumpets are doing exegesis, Otis: the appointed reading for Michaelmas is Revelation 12, Michael and his angels making war with the dragon, so the brass is the text rather than decoration. And Michaelmas was a quarter day too — rents due, servants hired — which is part of why the fair sat in the same week.
He'd done Michaelmas before, Otis — BWV 130, same feast, 1724, trumpets and drums again. Two years apart, same angels, fresh parts to copy.