The basis for the musical text of this study score was Henles revised edition of Part I published in 1997 and Yo Tomitas brand new revision of Part II (spring 2007). The eminent Bach scholar Tomita discusses the complicated source situation of Part II in an extensive preface. A detailed commentary rounds off the edition. Both parts of the Well-Tempered Clavier are also available as Henle Urtext editions with and without fingerings (HN 16 and HN 1016).