In his 'Preludes and Fugues,' Johann Sebastian Bach made decisive contributions to the development of this genre tradition. The importance of this work group in his own organ oeuvre is confirmed by the many transmitted sources: hardly any autographs, but all the more copies. The genesis of the works and the question of versions associated with it are described at length in the introduction. In his new edition, editor David Schulenberg occasionally makes a new evaluation of the transmitted sources. To do so, he based himself as faithfully as possible on the manuscripts that can be traced back to Bach or to his circle. Here the American Bach expert generally chooses one source as his principal one. Divergences from other sources are documented in the Commentary. On the whole, the new Urtext edition sometimes also emends some long-cherished readings of ornaments, voice leading and notation. Also printed in Volume 1 is, for example, the early version of the C major Prelude BWV 545 as well as the inserted Trio movement of the three-movement version of this work. As with the previously published volumes, the CD-ROM enclosed in Volumes 1 and 2 contains dubious works and secondary versions for comparison with the principal versions. This time, the CD-ROMs are completely in German and English and feature the English version of the Commentary.