Apart from various insignificant emendations relating to accidentals and ornamentation, this 1997 revision of Bach's Welltempered Clavier contains a remarkable correction in the musical text of the B minor prelude which so far has not been included in any modern edition. The present Wiener Urtext Edition deviates from the autograph which seems erroneous in bar 11, and was never revised by Bach himself, and instead follows the musically more logical early version which is supported by a correction by J.Fr. Agricola dating from his studies with Bach (ca. 1740).