Anatomy Room
Canon alla Ottava
Canon at 8th degree, 2 voices, 9/16, 103 bars


In two parts; the upper voice enters at first, then the lower voice follows it
at eighth degree lower, presenting the variant common theme in inverted
form at the beginning of the piece. The original form of the common theme
is in blue at the top column in the music below. This variant theme,
transforming its figure a bit, shows up at several times while it develops.
This music is composed as a fugal style looking very canon-like.



゛A゛, consecutive motif by two beat unit, and ゛B゛, consecutive motif by a
bar unit in the music are unique counter themes, respectively
accompanying to the first half of the theme and the latter. Then from bar 9,
this ゛A゛ comes along with the counter melody゛C゛, and ゛B゛the counter
melody ゛D゛. Interestingly, the theme to ゛A゛ takes ascending form while ゛C゛
takes descending.

The variant theme, seemingly a response to the theme, appears form bar 25.



This puts you mind of the theme in Cp.3. And the counter theme is getting
freer, although the image of ゛A゛ and ゛B゛ still remains in the melody.

The theme, inverted upside down, is stated from bar 41 and bar 62.



It is in dominant key from bar 41, and is in tonic key from bar 62.
You might notice that the head of the theme from bar 62 is embellished.

After the same theme as the beginning is exposed from bar 77, the music
between bar 5 and bar 80 is to be repeated.
This is what we call ゛Infinite canon゛.



After bar 81 is the repetition of bar 5.
Comparing the counter melodies between bar 77-80 with that of between
bar 81-84, you might notice that how different or variable they are in spit
of the same function as accompanying to the theme. This suggests the
infinite possibilities about Bach's counter theme technique.

The music is over when the repetition reaches bar 26.
Even here, Bach's counter theme art can be seen.



At bar 102, the upper voice jumps over the lower voice and finally arrives at
the lowest key among all in this piece.

Anatomy Room