| F♯ | C♯ | G♯ | D♯ | A♯ | E♯ | |||||||
| D | A | E | B | F♯ | C♯ | G♯ | D♯ | A♯ | E♯ | |||
| C | G | D | A | E | B | F♯ | C♯ | G♯ | ||||
| E♭ | B♭ | F | C | G | D | A | E | B | F♯ | |||
| G |
Measure 55 of this piece is:
The first half of this measure has the following tones within the matrix above:
| F♯ | C♯ | |||
| A | E | B | F♯ |
There are two versions of the F♯, implying that it undergoes a syntonic comma. In the bass part, that sounds particularly bad. Slowed down four times and with the syntonic comma rendered as a pitch slide, the first half of measure 55 sounds as follows:
To avoid this in the piece as a whole, I took the bold step to change Bach's notes as follows:
Actually, the syntonic comma in the bass can be avoided without changing Bach's notes, but then we would have to tolerate the harmonic fifth E-B with a pitch ratio of 40/27 instead of the ideal value of 3/2. The footprint of the first half of measure 55 exposes the non-ideal fifth E-B:
| B | F♯ | C♯ | |
| A | E |
Measure 55 then sound as follows (not slowed down):