Anatomy Room
Contrapunctus 9 a 4 alla Duodecima
Fugues with 2themes, 4 voices, 4/4 beat, 130 bars


゛alla Duodecima゛, that is, ゛by twelfth degree゛is titled, and the piece is
composed by double counterpoint at 12th degree. We discuss the details
later on.

The new theme unique to this piece is stated at the beginning.



The motif ゛A゛ and ゛B゛ in the music are employed many times in the piece,
sometimes as sequence.
The sequence by motive ゛A゛ are from bar 81 and bar 112 and so forth.
The sequence by motive ゛B゛ are from bar 66 and bar 85 and so forth.



The motif ゛B゛ in soprano, bass and alto are presented in order as if they
were chasing tenor at the tail of the theme from bar 27 in the above music.
The interesting thing is that each counter theme to the motive varies one
after another.

In parallel to the theme in tenor, the doubly-augmented common theme
appears in soprano from bar 35.



Please note that both themes begin with the same note. (d, d") The theme
in soprano and the common theme in bass are presented from bar 89.



This time, the common theme in bass starts at ゛d゛and the theme in
soprano is ゛a゛. In short, the theme placed at twelve degree higher than the
themes from bar 35. We call this relation that both themes are combinable,
double counterpoint, even shifted at twelfth degree. Canon alla Duodecima
is also composed by double counterpoint at twelfth degree as the title
shows.

The thematic combinations can be found from bar 35, 59, 73, 99 and 119,
and among these, the theme to the common theme is shifted at twelfth
degree higher in bar 35, 73 and 99.

The autograph reads that the common theme is written on its original
length, though here it is stated in augmented form. This resulted in the
compilation made at the first edition of the art of fugue, in which time value
was changed doubly.

You can see the thematic fragment in soprano from bar 75.



Another thematic fragment are performed from bar 85, and following
soprano and alto, the common theme in bass is lead afterwards from bar 89.



Stretto-like effect by fragments is caused in the case that stretto over the
whole theme is difficult or the theme is unrecognizable when making it
stretto.

Anatomy Room