Possibly the finest fugue ever written. It appears at the end of Clavieruebung III and is designed to represent the Trinity. To achieve this, its key signature is 3 flats; it has three subjects in three respective sections, the first subject appearing also with the 2nd and the 3rd subject ("3-in-1"); the number of bars in the three sections is 36, 45, 36 - the common factors of these two numbers are 3 and, of course, 1; etc, etc.
While playing, I had to turn the pages myself. Consequently, I recorded the fugue as three separate sections, then joined the three sections together. Unfortunately you can detect a slight discontinuity as one section leads onto the next.
This sample set has an unusually clear 32 foot reed, which brings out the final dramatic pedal entry of the 1st subject very well.