This piece is in
"Das Orgelbuch der Domorganisten"
("The Organ-Book of the Cathedral-Organists")
published by Bärenreiter BA 11217
Gereon Krahforst is now organist in the Benedict-Abbey "Maria Laach" in Germany. Prior to this he was Cathedral-Organist in Minden (GER), Paderborn (GER) and at the Basilica-Cathedral St. Louis (USA). He is a well known concert-organist, improvisator and composer.