Wohltemperirt Werckmeister/J. S. Bach:
Some mathematics


The 19 steps of the bearing plan in detail:
 

1 c1-c0 Descending octave from middle c
2 c1-f0 Descending pure fifth from middle c. Verify pure fourth c0-f0
3 f0-Bb Descending pure fifth
4 Bb-bb0 Transposition by ascending octave. Verify pure fourth f0-bb0
5 bb0-eb0 Descending pure fifth. Verify pure fourth Bb-eb0
6 eb0-eb1 Transposition by ascending octave. Verify pure fourth bb0-eb1
7 eb1-ab0  Descending pure fifth. Verify pure fourth eb0-ab0
8 g#0-c#0  Descending pure fifth
9 c#0-c#1 Transposition by ascending octave. Verify pure fourth g#0-c#1
10 c#1-f#0 Descending pure fifth, Verify pure fourth c#0-f#0
11 f#0-B Well-tempered fifth. Within the B-major triad the third B-d#0 must beat six times faster than the fifth B-f#0
12 B-b0 Transposition by ascending octave
13 b0-e0 Descending pure fifth. Check enlarged basic third c0-e0: must beat very slightly indeed from above. Verify pure fourth B-e0
14 e0-e1 Transposition by ascending octave
15 c0-g0 Well-tempered fifth, flattened. Must beat from below at the same rate as the third c0-e0 beats from above within the C-major triad. Beats slightly faster - virtually at the same pace - as the well-tempered fifth B-f#0 a semitone below
16 g0-d1 Well-tempered fifth. Flattened to beat 3/2-times faster than c0-g0
17 d1-d0 Transposition by descending octave
18 d0-a0 Well-tempered fifth. Beats hardly faster - virtually at the same rate - as c0-g0,  a whole tone below
19 a0-e1 Check: This must be a well-tempered fifth; e1 must not be changed. Compare beat-rate with g0-d1 a whole tone below. Play c-e-g and listen to this well-tempered C-major triad which opens the door to performing music in all 24 keys, both major and minor.