BWV 637--Durch Adam's Fall ist ganz verderbt from Orgelbuchlein by J.S. Bach

This is a continuation of the Orgelbuchlein I have been working through so far this year. Even through Covid-19. This is one of the most dramatic of the Chorale Preludes from the Orgelbuchlein, representing the fall of Adam in the dramatic descents of major and minor 7ths throughout the piece. In his daily blog on the Orgelbuchlein, organist Raymond Nagem says this about this prelude:

Bach takes his cue from the first two lines of the chorale text: “Durch
Adams Fall ist ganz verderbt / Menschlich Natur und Wesen” (Through
Adam’s fall human nature and character is completely corrupted). It’s
even been suggested that the chromatic inner voices represent the
wriggling of the snake. The sound of the piece is highly disturbing; Bach
doesn’t spare his listener. If the text suggests the image of something
“completely corrupted,” Bach has no problem writing music that sounds
completely corrupt and rotten.
However, there is also in the accompaniment a rising three note figure, that Schweitzer calls the "Joy motive" that makes it's appearance, thought to be taken from the chorale's text: Ohn' Gottes Trost, der uns erlöst Hat von dem großen Schaden (translated: without comfort from God, who has redeemed us
from the great harm). It is a wonderful contrast of hope in the midst of despair worthy of Shakespeare.