The theme, inverted from the common theme in the Cp.1, is stated at the
beginning. It was born from pivoting the third note of ゛ｆ゛.
So-called ゛Cuckoo゛derives from the sequential motif shown later.
The counter theme accompanied with the response is transformed flexibly
throughout the piece, along with the theme.
In Cp.3, this theme and the response are switched, that is, the response
used here is equal to the theme in Cp.3.
Two different sequences ゛A゛ and ゛B゛ starts with bar 19 in the music.
Among the sequence ゛A゛, the motive of soprano and alt have this piece
called ゛Cuckoo゛, and that repeatedly show up in this entire piece、not
always as a sequence though.
The sequence ゛A゛ can be seen from bars 43, 53, 87,103 while the
sequence ゛B゛ from bars 98, 124, slightly transforming their figures.
Simultaneity of the thematic tonal variance and the music transposition
results in successive plural themes, giving a major musical flow, which can
be seen from bar 61 below.
The theme in bass from bar 61 modulates from F major to C major and G
minor as well as the theme in tenor from bar 65 changes from G minor to D
minor, exhibiting the harmonic development. Also, you will find the serial
thematic exposition along with the transposition from bar 27 and bar 73.
From bar 107, the syncopated variant theme appears, parallel to the original
theme.
The variant themes are exposed in bass from bar 107 and in soprano from
bar 111. The former comes half beat behind while the latter, half beat
before.
Often said personal seal, the order of ゛b-a-c-h゛ is secretly woven into the
coda, however, is hard to recognize if no one tells it.
