(A2) of the theme in the minor key contains typically French harmonic progressions:Second theme: God, the SonThis theme, representing God, the Son, the "kind Lord", has two bar phrases of staccato three-part chords in the galant style, with echo responses marked piano. This is followed by a more ornate syncopated version which is not further developed during the prelude:Third theme: the Holy GhostThis theme is a double fugue based on semiquavers, representing "the Holy Ghost, descending, flickering like tongues of fire." The semiquavers are not marked with slurs, according to North German conventions. In the final development (C3) the theme passes into E minor, presaging the close of the movement, but also harking back to the previous minor episode and anticipating similar effects in later movements of Clavier-Übung III, such as the first duet BWV 802. The older style two- or three-part writing forms a contrast to the harmonically more complex and modern writing of the first theme. The semiquaver subject of the fugue is adapted for the pedal in the traditional way using alternating foot technique: BWV 552/2 Fuga The fugue in E major BWV 552/2 that ends Clavier-Übung III has become known in English-speaking countries as the "St. Anne" because of the first subject's resemblance to a hymn tune of the same name by William Croft, a tune that was not likely known to Bach. A fugue in three sections of 36 bars, 45 bars and 36 bars, with each section a separate fugue on a different subject, it has been called a triple fugue. However, the second subject is not stated precisely within the third section, but only strongly suggested in bars 93, 99, 102-04, and 113-14.The number threeThe number three is pervasive in both the Prelude and the Fugue, and has been understood by many to represent the Trinity. The description of Albert Schweitzer follows the 19th-century tradition of associating the three sections with the three different parts of the Trinity. The number three, however, occurs many other times: in the number of flats of the key signature; in the number of fugal sections; and in the number of bars in each section, each a multiple of three (3 × 12, 3 x 15), as well as in the month (September = 09 or 3 x 3) and year (39 or 3 x 13) of publication. Each of the three subjects seems to grow from the