The original source of this piece in manuscript Am B 340 is a manualiter Toccata in D Dorian by Johann Pieterszoon Sweelinck. This Toccata is actually the source for two different pieces. The first piece was published a week ago. This second pieces is based on two different fragments from the same Toccata. They are in the reverse order from Sweelinck's original. I have no idea why this was done, but fact is that if you don't know the original, the arangement of musical material sounds logical and natural. As said already in other posts, Manuscript Am.B. 340, as a source of works by Scheidemann or Sweelick or others, has been called "utterly unreliable". Nevertheless, I very much like these "utterly unreliable" pieces.
Score available here: http://partitura.org/index.php/wilhelm-karges-jan-pieterszoon-sweelinck-fantasia-2