Difficult stuff ... Working with the organ music of Johann Ludwig Krebs invites to enter a large world of a Johann-Sebastian-Bach-nostalgy. Krebs fights for to find his own place and style therein. Krebs developes harmonies which are even more experimental than those of Bach. And Krebs is also an splendid composer in respect of the polyphonic structures of his Fugues. Some of his Chorale Preludes are copies of existing compositions from his master. Other Choral Preludes performe some musical Bach-ideas.
His major Preludes and Fugues are musical giants. Krebs loved the music of his master so long that he couldn't stop to perform them. The Preludes and Fugues in G and in d contain very long Pedal-soli. How to play them? If one "thunder down" them he will get long boring technical Etudes. I suggest to understand them as independing excerpts from fictive Sonatas for Viola di gamba and to play them in this way. So one will get philosophical monodies with suprising details. Listening to this Preludes you must take your time. You will recognize many musical elements of Johann Sebastian Bach in new connections and in "new clothes". The form of Krebs's Preludes is more an improvisation than a composition.
The opus optimum of Johann Ludwig Krebs is Praeludium et Fuga in d. The Fugue is a Quadrupel-Fugue in a way: first part with the first subject, second part with the second subject, third part with the first and the second subject, third part with the first mirror-subject, last part with the first original and the first mirror-subject.