freely imitated by the treble in contrary motion. It must be noticed that, though the fugue is for four voices, both the episodes are in three parts. This is very common in four-part fugues; it would be bad for all the voices to be continually at work throughout. Three-part, and even two-part, harmony is often met with, especially in the episodes, furnishing relief and contrast. In the four-part fugue in F minor (No. 12 of the same work), five out of the six episodes are for three voices only.
220. In our next example the episodes are formed from the countersubject. The subject and countersubject of the fugue are the following—
We have quoted the codetta preceding the entry of the third voice, because (as we shall see directly) it is used at the beginning of the first episode, though it does not appear in the others.
221. This fugue contains three short episodes.
![\new ChoirStaff << \override Score.TimeSignature #'stencil = ##f
\new Staff \relative e'' { \key fis \minor \time 6/4 \partial 2. \mark \markup \tiny { (\italic"b") } <<
{ e4 d2 | d4 cis2 ^~ cis4 b2 ^~ | b8[ gis a cis] } \\
{ cis2 fis,4 | b4. e,8[ fis gis] a2 d,4 | cis2 } >> }
\new Staff \relative a { \key fis \minor \clef bass
ais8 b b a a gis |
gis fis e b' a gis fis gis gis fis fis eis | eis4 fis } >>](http://upload.wikimedia.org/score/9/0/90pim55p62u49a2we84l5cmatth4cs9/90pim55p.png)
