(1) The author would like to thank Dr Alan Marsden for his invaluable comments and advise on this article.

(2) Yo Tomita: J. S. Bach's 'Das Wohltemperierte Clavier II': A Critical Commentary, I (Leeds: Household World, 1993), II (1995); J. S. Bach: The Well-Tempered Clavier, Part II. Edited and annotated by Richard Jones, Commentaries by Donald Francis Tovey (London: The Associated Board of the Royal Schools of Music, 1994); Alfred Dürr, Kritischer Bericht to Johann Sebastian Bach, Neue Ausgabe Sämtlicher Werke, Serie V, Band 6.2. Das Wohltemperierte Klavier II (Kassel, et al. Bärenreiter, 1996).

(3) Of these two sets, one set has survived in incomplete form, containing 21 prelude-fugue pairs —Add. MS 35 021 in the possession of the British Library, London, which was compiled during the years 1739-1742. The other set is lost, but its text is reflected closely in half a dosen copies stemming from it. The most important is the 1744 copy by Bach's future son-in-law, Johann Christoph Altnickol (1719-1759), Mus. ms. Bach P 430 in the possession of the Staatsbibliothek zu Berlin Preußischer Kulturbesitz.

(4) Tomita: A Critical Commentary, II, p.v.

(5) Tomita: A Critical Commentary, II, pp. 1-1001. This database was constructed in such a way that the data in its original form can be used as a useful reference book for the work, and at the same time, in its electronic form they can be analysed using more powerful techniques with the aid of computers.

(6) The basic concept of the data compilation is discussed in the author's article 'The Spreadsheet in Musicology: An efficient working environment for statistical analysis in text critical study' in Musicus III (1993) 31-37.

(7) Edward H. Shortliffe: MYCIN: Computer-Based Medical Consultations (New York: Elsevier, 1976). Based on a PhD thesis, Stanford University, Stanford, CA, 1974.

(8) John Self: 'Dormorbile: a vehicle for metacognition'. In: Emerging Computer Technologies in Education. Edited by T. W. Chan and J. A. Self. (Charlottesville: AACE, 1995)

(9) ?? (book currently on loan to AM)