Perhaps Bach's greatest organ work, at any rate the one he saw fit for engraving himself, a very costly enterprise in those days.
The Es dur Fugue follows this piece not directly, being the opening and closing of the Organ Mass bach wrote, the "Dritter Teil der Klavierubung".
The Praeludium is a French Overture with the typical rythmic figures and interludes.
I tried to play the whole piece "in one gush", not varying much in the rythm and accentuation.
For information on the Prel and the Fugue I recommend looking it up on the internet: there's loads there.
!!! Happy New Year to everyone on the Concert Hall and not in the least the moderators of this fine website we all love and use !!!