Johann Sebastian Bach Preludes, Toccatas, Fantasias and Fugues II / Early Versions and Variants to I (Volume 5) and II (Volume 6). Johann Sebastian Bach: Complete Organ Works in revised editions. The present volume is an updated edition of Series IV, Volume 6 of the “New Bach Edition” (NBA), prepared by Dietrich Kilian in 1964. The discovery of new sources and a reassessment of existing handwritten copies have brought about changes to the contents of the volume, which now includes the “Fantasia"