The opening -- at (a) and (b) -- gives us a very compact "mirror": from Dorian ^8 down to ^5 and back up again. At (c) and two later places (arrows), an expressive upper note F5. At the end, the figure of (a) is repeated with a repetition of its head (also boxed) and then the cadence line follows: (e), which is a variant of (b). The surprising restriction on range is typical of published instrumental ensemble music through as late as 1650.
