Here the first countersubject accompanies the answer; when the third voice enters with the subject, the alto, which has just completed the answer, takes up the first countersubject, while the treble continues with a second countersubject. Every subsequent entry of the subject or answer down to the end of the fugue is accompanied by both the countersubjects.
174. A different method of employing two countersubjects will be seen in the 47th fugue (in B major) of the same work. The first appearance of the answer is accompanied by a countersubject.
J. S. Bach. Wohltemperirtes Clavier, Fugue 47.
![\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f)
\new Staff \relative f { \clef tenor \time 2/2 \key b \major R1*4
\[ fis2^"A" ais | dis b | gis eis' | fis4 \] }
\new Staff \relative b, { \clef bass \key b \major
\[ b2^"S" dis | gis e | cis ais' | b4 \] ais8 gis fis4 e |
dis8 cis \[ e2^"CS1." dis8 cis |
b fis' ais2 gis8 fis | eis b' dis2 cis8 b | ais4 \] } >>](http://upload.wikimedia.org/score/1/u/1uxwb3373snjxe0q1x5wrk2clsjkrsr/1uxwb337.png)
This is regularly introduced against subject and answer throughout the whole of the exposition, after which it is heard no more. Its place is taken on the next entry of the subject by an entirely new countersubject, written in double counterpoint in the twelfth, and invariably inverted in that interval. We gave it as an illustration of this species of counterpoint in § 171 of Double Counterpoint, to which the student is referred. It is very rare to find two different countersubjects used, not simultaneously, but as here, successively.
