Fugue (Prout)/Chapter 7

From Wikisource
Jump to navigation Jump to search



213. Though we occasionally meet with fugues in which the subject or answer is almost continuously present, a striking and well-known example being the first fugue in the 'Wohltemperirtes Clavier,' it is generally advisable to give variety to the composition by the introduction of episodes. An Episode, is that part of a fugue in which for a time neither subject nor answer is heard. In the majority of cases the reappearance of the subject attracts more attention and excites more interest, if it has been absent for a while.

214. There is another important purpose also served by the episode. So long as subject and answer continue to enter (as in the exposition) at the distance of a fourth or fifth from one another, it is clear that we shall not get away from the tonic and dominant keys; and although in the middle section of a fugue we often find entries at other distances than the fourth and fifth, it is frequently more convenient to effect the modulations by means of episode than to do so by varying the distances of entry, which would sometimes necessitate more or less important changes in the form of the subject itself. How modulations can be made during an episode will be seen presently.

215. The student must be careful to distinguish between an episode and the codetta spoken of in the last chapter. When a codetta appears between the second and third entries in the exposition, it often has much the same character as an episode; the difference is, that the former appears in the course of the exposition, and the first episode never till its close. This will be clearly seen from the following example, in which the codetta and the first episode are composed of nearly the same material.

J. S. Bach. Wohltemperirtes Clavier, Fugue 2.

\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.Rest #'style = #'classical
  \new Staff \relative g'' { \key c \minor \time 4/4 <<
    { R1*2 r8 g16^"A" fis g8 c, ees g16 f g8 a |
      d, g16 fis g8 a c,16 d ees4 d16 c | %over the page
      bes8 ees16_\markup \tiny \italic "Codetta." d ees8 g,
        aes f'16 ees f8 a, |
      bes g'16 fis g8 b, c d16 ees f4 ~ |
      f8 ees16^"CS" d c bes aes g f8 aes' g f |
      ees d ees f b, c d b |
      c g'16_\markup \tiny \italic "Episode." fis g8 d ees4 r8 e8 |
      f f16 e f8 c d4 r8 d | ees s } \\
    { r8 c16_"S" b c8 g aes  c16 b c8 d |
      g, c16 b c8 d f,16 g aes4 g16 f |
      ees c' b_"CS" a g f ees d c8 ees' d c |
      bes a bes c fis, g a fis | %over the page
      g4 r16 c, d ees f g aes8 ~ aes16 d, ees f |
      g a bes8 ~ bes16 ees, f g aes g f ees d8 c'16 b |
      c4 r r8 f ees d | r aes g f g f16 ees f8 d |
      g4 r8 b c c16 b c8 g |
      aes4 r8 a bes bes16 a bes8 f g4_"&c." } >> }
  \new Staff \relative c' { \clef bass \key c \minor R1*6
    r8 c16_"S" b c8 g aes c16 b c8 d |
    g, c16 b c8 d f,16 g aes4 g16 f |
    ees c' b a g f ees d c d ees d c bes aes g |
    f bes' aes g f ees d c bes c d c bes aes g f | ees s s8 } >>

Here the answer ends on the third of the dominant; a codetta is therefore introduced (§ 193) to lead back naturally to the key of the tonic, in which the subject reappears. The codetta is made from a modified form of the first notes of the subject treated sequentially, and accompanied (also sequentially) by the first notes of the countersubject in inverse movement. This is not an episode, because the exposition is not yet complete. The subject then enters in the bass, with the countersubject above it. No additional entry being here required, as the subject was announced by the middle voice (§ 186); the exposition ends here, and is followed at once by the first episode.

216. If we examine this episode, we shall see that it is made from the same material as the codetta, but with different treatment. The two upper voices have a theme founded on the first notes of the subject, the alto imitating the treble as a canon in the fifth below. The bass gives the commencement of the countersubject, not (as in the codetta) by inverse movement, but in its direct form. Observe also how, by means of sequence, a modulation is effected to the key of the relative major, in which key the subject follows in the treble voice immediately on the conclusion of the above extract.

217. We said in Double Counterpoint (§ 307) that imitation was a most important ingredient in fugue, and the quotation just given will show how it is to be used. Except in a stretto, the construction of which will be explained in our next chapter, imitation is seldom found during the entries of the subject itself; but it is almost constantly employed in the episodes. By this means unity of character is given to this part of the work, and anything like patchwork is avoided.

218. It is for the same reason that we mostly find the episodes of a fugue formed, either wholly or in part, from material already met with, either in the subject, countersubject, or codetta. We give examples of each. In the sixteenth fugue of the 'Wohltemperirtes Clavier,' the following is the subject.

\relative d' { \clef bass \key g \minor \time 4/4 r8 d ees g, fis4 g | r8 \[ a16 bes c8 bes16 a bes4 \] }

The fugue contains two episodes, both founded on the second bar of this subject.

J. S. Bach. Wohltemperirtes Clavier, Fugue 16.

\new ChoirStaff <<
  \new Staff = "up" { \key g \minor \time 4/4 
    \new Voice \relative e' { \stemUp
      e8 d g4 ^~ g16 fis g a bes4 ^~ | bes a ^~ a16 d, e fis g4 ^~ |
      g8 fis16 g a8 g16 f g4. c8 | f, g16 a bes2 a4 | bes } }
  \new Staff = "down" { \key g \minor \clef bass <<
    \new Voice \relative f { \stemUp
      f8 g16 a bes8 a16 g a8 bes16 c d8 c16 bes | \change Staff = "up"
      \stemDown c2. bes8 ees! | \change Staff = "down" \stemUp
      a,16 bes a bes c8 bes16 a bes8 \change Staff = "up" \stemDown
        c16 d ees4 _~ | ees d c2 | d4 }
    \new Voice \relative d { \stemDown
      d1 | e8 a16 g fis8 g16 a bes,8 c16 d ees8 d16 c |
      d2 g,4. a8 | bes f' g d ees d16 ees f8 f, | bes4 } >> } >>

In this episode the figure marked with a |   | is seen in the different voices in turn, by direct, and once by inverse movement. In the last bar, where a modulation is made to the relative major, the imitation is merely rhythmic.

219. The second episode is rather more elaborate.

\new ChoirStaff << \override Score.TimeSignature #'stencil = ##f
  \new Staff = "up" { \key g \minor \time 4/4 \partial 2 <<
    \new Voice \relative g'' { \stemUp
      g8 r r16 d c bes | a4 ^~ a16 bes c d g,4 ^~ g16 bes aes g |
      f4 ^~ f16 g aes bes ees,4 ^~ ees16 g f ees |
      d4 ^~ d16 d e fis g4 ^~ g16 bes a g | fis8 s }
    \new Voice \relative b' { \stemDown
      bes16 d, e fis g4 _~ | g16 g f ees d4 _~ d16 bes c d ees4 _~ |
      ees16 ees d c bes4 _~ bes16 g a b c4 _~ | c16 \stemUp
      \change Staff = "down" c bes a g4 ^~ g16 g a bes \stemDown
      \change Staff = "up" c8 cis | d4 } >> }
  \new Staff = "down" { \key g \minor \clef bass
    \new Voice \relative g, { \stemDown
      g8 g'16 a bes8 a16 g |
      d'8 d,16 ees f8 ees16 d ees,8 ees'16 f g8 f16 ees |
      bes'8 bes,16 c bes8 c16 bes c,8 c'16 d ees8 d16 c |
      g'8 g,16 a bes8 a16 g ees'2 | d4 } } >>

Here the bass treats the last part of the subject sequentially, while the figure of counterpoint propounded by the alto is 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—

J. S. Bach. Wohltemperirtes Clavier, Fugue 14.

\new ChoirStaff << \override Score.Rest #'style = #'classical \override Score.BarNumber #'break-visibility = #'#(#f #f #f)
  \new Staff \relative c' { \key fis \minor \time 6/4 R1.*3
    r4 cis^"A" dis e2. ~ | e4 dis8 eis fis4 ~ fis eis8 dis eis fisis |
    gis4. fis8 e gis fis e dis2 |
    cis8 e_\markup \tiny \italic "Codetta." fis gis a4 ~
      a8 fis gis ais << { b4 ~ b8 b b a a gis_"&c." } \\
                        { s4 fis cis b } >> }
  \new Staff \relative f { \clef bass \key fis \minor
    r4^"S" fis gis a2. ~ | a4 gis8 ais b4 ~ b ais8 gis ais bis |
    cis4. b!8 a! cis b a g2\mordent |
    fis2. r8^"CS" cis' cis b b ais |
    ais b b a a gis gis2 ~ gis8 ais | bis cis dis4 gis, cis2 bis4 |
    cis4. b8 cis dis e4. cis8 dis eis | r4 fis,,^"S" gis } >>

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.Rest #'style = #'classical \override Score.TimeSignature #'stencil = ##f
  \new Staff \relative f' { \key fis \minor \time 6/4 \mark \markup \tiny { (\italic"a") } <<
    { fis8 a b cis d4 ^~ d8 b cis dis e4 ^~ |
      e8 d d cis cis bis bis4 cis2 ^~ | cis4 bis2 cis8 } \\
    { cis,4. gis'8 a b e,4. a8 b cis |
      fis,2. _~ fis8 fis fis e e dis |
      dis gis gis fis fis e e4 } >> }
  \new Staff \relative a { \clef bass \key fis \minor <<
    { a4 r r } \\
    { fis4. eis8 fis gis a4. fis8 gis ais |
      b b, b a a gis gis a' a gis gis fis | fis4 gis gis, cis } >> } >>

\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 } >>

\new ChoirStaff << \override Score.TimeSignature #'stencil = ##f
  \new Staff \relative a' { \key fis \minor \time 6/4 \mark \markup \tiny { (\italic"c") } <<
    { a2. ^~ a8 cis b a a gis |
      gis2. ^~ gis8 b a g g fis | fis eis fis4 } \\
    { gis8 gis fis e e dis dis2. _~ |
      dis8 fis e d d cis cis2. _~ | cis4 b2 } >> }
  \new Staff \relative c' { \clef bass \key fis \minor <<
    { cis8 e dis cis cis b b2. ^~ |
      b8 d cis b b a a2. ^~ | a4. } \\
    { fis2. _~ fis8 a gis fis fis e |
      e2. _~ e8 gis fis e e d | d2. } >> } >>

The first bar of (a) consists of the codetta, with the addition of a middle part; the rest of it, as will be seen, is made out of the first notes of the countersubject. At (b) the same theme is seen in the bass, with free upper parts; while at (c) it is treated sequentially, the outer parts which move in tenths imitating the inner parts moving in thirds. Here again, though the fugue is for four voices, two out of the three episodes are in only three parts.

222. In § 191 we gave the subject of the seventh fugue in the 'Wohltemperirtes Clavier.' In the second bar was seen a codetta before the entry of the answer, the reason for which we showed. From this codetta the episodes of the fugue are chiefly developed.

J. S. Bach. Wohltemperirtes Clavier, Fugue 7.

\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.Rest #'style = #'classical
  \new Staff \relative b'' { \key ees \major \time 4/4 \partial 2 \mark \markup \tiny { (\italic"a") } <<
    { bes2 ^~ | bes16 bes g ees des bes' g des c8 ees aes4 ^~ |
      aes16 aes f d c aes' f c bes8 d g4 ^~ |
      g ^~ ^~ g16 c, d ees f4. ees8 ^~ | ees16[ d] } \\
    { d8 f d bes | ees r r4 r8 ees c aes |
      d r r4 r8 d bes g | c bes aes4 _~ aes16 c bes aes g4 | f } >> }
  \new Staff \relative b { \clef bass \key ees \major
    bes16 f' d bes aes f' d aes |
    g8 ees' r ees, aes16 ees' c aes g ees' c g |
    f8 d' r d, g16 d' bes g f des' bes f |
    e c' g e f c' aes f d bes' f d ees bes' g ees | bes8 } >>

In this episode the codetta is treated by sequential imitation between the outer parts with a middle part, made from the augmentation of the semiquaver figure of the bass. The first part of the next episode

\new ChoirStaff << \override Score.Rest #'style = #'classical \override Score.TimeSignature #'stencil = ##f \override Score.BarNumber #'break-visibility = #'#(#f #f #f)
  \new Staff \relative e'' { \key ees \major \time 4/4 \partial 2 \mark \markup \tiny { (\italic"b") }
    << { ees16 bes' g ees des bes' g d | c8 aes' } \\ { ees8 r s4 c } >>
    r8 aes d16 aes' f d c aes' f c | %over the page
    b8 g' r g, c16 g' e c bes g' ees bes |
    a g' c, g aes f' d a g f' d b g ees' c g |
    fis ees' c fis, f d' b f e d' b g ees c' g ees |
    d c' a f d b' a b c8 }
  \new Staff \relative e' { \clef bass \key ees \major <<
    { s4 ees ^~ | ees16 ees c aes g ees' c g f8 aes d4 ^~ | %over page
      d16 d b g f d' b f e8 g c4 ^~ |
      c b8 c d r r4 | s1 | r2 c16[ bes] } \\
    { g8 bes g ees | aes r r4 r8 aes f d | %over page
      g8 r8 r4 r8 g e c | f ees d c b g c bes |
      a a' b g c g aes ees | f ees16 f g8 g, c } >> } >>

is an inversion of the preceding, the augmentation being now in the bass. By the substitution in the third bar of B natural for the B flat of our preceding quotation, a modulation is effected to the key of the relative minor. The figure of the codetta is maintained in the upper part till the end of the episode, the last two bars of which are in two-part harmony only.

223. In another episode in the same fugue, of which we give only the beginning,

\new ChoirStaff << \override Score.Rest #'style = #'classical \override Score.TimeSignature #'stencil = ##f \override Score.BarNumber #'break-visibility = #'#(#f #f #f)
  \new Staff \relative g'' { \key ees \major \time 4/4 \mark \markup \tiny { (\italic"c") } <<
    { g16 d c d bes e d e g8 f r |
      f16 c bes c aes d c d f8 ees r4 } \\
    { bes4 bes bes16 des c bes aes g f g |
      aes4 aes _~ aes16 c bes aes g f ees f_"&c." } >> }
  \new Staff \relative g { \clef bass \key ees \major
    g16 bes aes bes g aes f g e c' aes f c f c aes |
    f aes' g aes f g ees f d bes' g ees bes ees bes g } >>

the codetta has only a subordinate part; it evidently suggested the arpeggio figure which is seen in the bass in the second half of each bar. The chief figure here is the sequence, the theme of the upper voice being a modification of the subject of the fugue. In our last example from this fugue,

\new ChoirStaff << \override Score.Rest #'style = #'classical \override Score.TimeSignature #'stencil = ##f \override Score.BarNumber #'break-visibility = #'#(#f #f #f)
  \new Staff \relative b' { \key ees \major \time 4/4 \partial 2 \mark \markup \tiny { (\italic"d") } <<
    { bes8 f' d bes | bes'2 ^~ bes8 ees, c aes |
      aes'2 ^~ aes8 d, bes g |
      g'4 ^~ g16 c, d ees f ees d c bes aes bes c | f,4 } \\
    { d8 r r4 | r16 bes' ees g des bes des g c,8 r r4 |
      r16 aes d f c aes c f bes,8 r r4 |
      r8 bes aes2 g8 ees _~ | ees16[ d] } >> }
  \new Staff \relative b, { \clef bass \key ees \major
    bes16 f' d bes aes f' d aes |
    g8 g' r ees, aes16 ees' c aes g ees' c g |
    f8 f' r d, g16 d' bes g f d' bes f |
    e c' g e f c' aes f d bes' f d ees bes' g ees | bes'8 } >>

the same material is used as in our quotations (a) and (b). In its general character this episode much resembles (a); but the figure taken from the codetta is now allotted to the two lower voices, and is seen in the alto by free inversion, and in the treble by augmentation.

224. As all our examples hitherto have been from Bach, we will now give one by Handel. The second of his 'Six Fugues for Organ or Harpsichord' is particularly rich in interesting episodes. We first give the subject and countersubject.

Handel. Six Fugues, No. 2.

 \new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f)
  \new Staff = "up" \relative d'' { \key g \major \time 4/4 \mark \markup \tiny { (\italic"a") }
    r2 r8 \[ d^"S" d d | b4 g a b | c8 c, c c c c c c |
    fis c ~ c b a g' fis4 | \stemUp
    g8[ \] fis^\markup \tiny \italic "Codetta." g a] b4. c8 |
    a4 r8 d^"CS" c4. d16 c | b8 a g fis e d cis b |
    a4 a' g4. a16 g | fis4 }
  \new Staff = "down" << \clef bass \time 4/4
    \new Voice \relative g' { s1 s s s \change Staff = "up" \stemDown
      s2 r8_"A" g g g | fis4 d e fis |
      g8 \change Staff = "down" g, g g g g g g |
      cis g ~ g fis e d' cis4 | d }
    \new Voice { R1*5 s1 } >> >>

In the first episode that we shall quote,

\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.TimeSignature #'stencil = ##f
  \new Staff = "up" \relative d' { \key g \major \time 4/4 \partial 2 \mark \markup \tiny { (\italic"b") } <<
    { d2 | r8 g g g fis4 d | e8 a a a g4 e | fis8 b b b a4 fis |
      g8 a16 b c4 ^~ c8 b b a16 g | r8 d'^"S" d d } \\
    { a,2 | b4 s2. | s1 | s4 d c4. d16 c |
      b8 \change Staff = "down" \stemUp g \stemDown \change Staff = "up" e' fis16 g d2 | a' } >> }
  \new Staff = "down" \relative g << \clef bass \key g \major
    { g4 fis | g r8 b a4. b16 a | g4 c b4. c16 b |
      a4 s2. s1 d2 } \\
    { r8 d, d d | b4 g a b | c a b c | d b c d |
      e4. d16 e fis4 g _~ | g fis } >> >>

the first notes of the subject in the bass are imitated at half a bar's distance by the treble, and also accompanied by the countersubject in the middle voice in double counterpoint in the tenth; the passage is twice sequentially repeated, after which an inverted cadence brings back the subject.

225. The following episode

\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.TimeSignature #'stencil = ##f \override Score.Rest #'style = #'classical
  \new Staff \relative b'' { \key g \major \time 4/4 \mark \markup \tiny { (\italic"c") } <<
    { r8 b b b gis d d d | cis g g g r d' d d |
      c!4 a b8 e e e | d4 b cis8 fis fis fis |
      e4 cis d8 e16 fis g4 ^~ | g fis8 g e2 } \\
    { dis,4 s2. | s2 fis4 r | r a g4. a16 g |
      fis4 b a4. b16 a | g4. g8 fis d b' cis16 d |
      a2 r8_"A" g g g } \\
    { b4 } >> }
  \new Staff \relative b { \key g \major \clef bass
    b4 b e gis, | a cis d d, | e fis g e |
    fis g a fis | g a b4. b8 | cis a d2 cis4 } >>

begins with repetitions of the first four notes of the subject (or answer), after which the same material is employed as in episode (b); but the notes of the countersubject are now used against a different part of the subject. The episode from which we shall next quote is too long to be given entire.

\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.TimeSignature #'stencil = ##f \override Score.Rest #'style = #'classical
  \new Staff \relative f' { \key g \major \time 4/4 \mark \markup \tiny { (\italic"d") } <<
    { fis8 c ~ c b a g' fis4 | g8 f ~ f e d c' b4 |
      c8 g ~ g fis e d' cis4 | d8 a ~ a g fis e' dis4 |
      e8 b e4 fis4. e16 fis | g4 b, cis4. b16 cis | d4 d e4. d16 e |
      fis4 a, b4. a16 b | c8 a e'4 d4. e16 d |
      c4 r8 f e4. f16 e | d8 } \\
    { d,4 s2. s1 s s | s s s | s s4 r8 c b a' gis4 |
      a8 e f4 g a | b_"&c." } >> }
  \new Staff \relative d, { \clef bass \key g \major
    d4 d' c4. d16 c | b4 g' f4. g16 f |
    e4 a g4. a16 g | fis4 b a4. b16 a |
    g4 r8 g fis e' dis4 | e8 e, ~ e d cis b' ais4 |
    b8 g ~ g fis e d' cis4 | d8 d, ~ d c b a' gis4 |
    a4 a, b4. a16 b | << { r4 r8 d' c4. d16 c | b4 } \\
                         { c, d e f | g } >> } >>

Here the last notes of the subject and countersubject (instead of the first, as hitherto) are developed. The first four bars of our extract show a sequential treatment of a one-bar theme; at the fifth bar, the subject is in the bass, and is accompanied by the countersubject in inverse movement. At the ninth bar, the close of the subject is in the middle voice, and is accompanied by the countersubject, in direct movement above, and in inverse movement below.

226. Two more short passages will conclude our examples from this fugue.

\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.TimeSignature #'stencil = ##f \override Score.Rest #'style = #'classical
  \new Staff \relative a' { \key g \major \time 4/4 \mark \markup \tiny { (\italic"e") } <<
    { a2 g4 g | a b c a | b c d8 d d d |
      c4 a b e d4. e16 d cis4 } \\
    { g4 fis d s | s1 | s2. d4 |
      e fis g e | fis g g_"&c." } \\
    { \stemDown d2 } >> }
  \new Staff \relative b { \clef bass \key g \major <<
    { s2 r4 b | a4. b16 a g8 r c4 | b4. c16 b a4 s } \\
    { r8 d, d d b g' g g | fis4 d g8 e e e | g4 e fis b |
      a4. b16 a g4 c ~ | c b a } >> } >>

Here we see two inversions of the subjects of episode (b). Though the second one, in which the original countersubject is in the bass, is not developed at any length, enough is given to show that the passage is written in triple counterpoint.

\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.TimeSignature #'stencil = ##f \override Score.Rest #'style = #'classical
  \new Staff = "up" \relative e'' { \key g \major \time 4/4 \mark \markup \tiny { (\italic"f") } <<
    { r4 e d c | b d c b | a c r8 d d d |
      e4 g fis e | d fis e d | cis } \\
    { s1 s s2 b4 a | g b a g | fis a g fis | e } >> }
  \new Staff = "down" \relative c' { \clef bass \key g \major <<
    { \change Staff = "up" \stemDown c4  g' a4. g16 a |
      b4 fis g4. fis16 g | \showStaffSwitch 
      a4 fis8 e \change Staff = "down" \stemUp d4 fis |
      e4. b8 cis4. b16 cis | b4 } \\
    { a8 e e e fis4 a | g8 d d d e4 g | fis8 d d d g4 d' |
      d g, a4. g16 a | b4 r8 fis g4. fis16 g | a4 } >> } >>

In the first bars of this passage we see the second and third bars of (b) treated by inverse contrary movement (Double Counterpoint, § 454). In the fourth bar we see the inverted subject in sixths accompanied by the inverted countersubject in thirds.

227. Occasionally the episodes of a fugue are formed from entirely fresh material. In this case care must be taken that the new matter is in keeping with what has preceded. An example of episodes of this kind will be found in Bach's Organ Fugue in D minor, arranged from one of his violin fugues—

\relative a' { \key d \minor \time 4/4 r8 a a a a g16 f g8 e | f }

We give extracts from two of the episodes.

J. S. Bach. Organ Fugue in D minor.

 \new ChoirStaff << \override Score.Rest #'style = #'classical \override Score.BarNumber #'break-visibility = #'#(#f #f #f)
  \new Staff \relative c'' { \key d \minor \time 4/4 \partial 2 \mark \markup \tiny { (\italic"a") } <<
    { cis8 r r16d s8 | r16 e, gis b c e a, g r a c ees d c b a |
      bes d, g a bes d g, f r g bes d c bes a g | a_"&c." } \\
    { g16 bes a g f8 e16 d } >> }
  \new Staff \relative a { \clef bass \key d \minor <<
    { <a e'>8 r r4 | a8 r r4 <a fis'>8 r q r |
      <g g'> r r4 <g e'>8 r q r | <f c'> } \\
    { a,8 s s4 | a8 s s4 d8 s d, s |
      g s s4 c8 s c, s | f } >> } >>

\new ChoirStaff << \override Score.TimeSignature #'stencil = ##f
  \new Staff \relative c'' { \key d \minor \time 4/4 \mark \markup \tiny { (\italic"b") } <<
    { c8 b c d e f e d | c b c d e d e fis | gis } \\
    { a,8 gis a b c d c b | a gis a b c b c a | b } \\
    { s1 s4. f8 a } >> }
  \new Staff \relative c' { \clef bass \key d \minor <<
    { <c e,>8 r r <f gis> <e a> r r <f gis,> |
      <e a,> r r <d f,> <c e,> r r <c a> <d f,>^"&c." } \\
    { a,1 _~ a _~ a1*1/2 } >> } >>

Another good example of the same kind will be seen in Bach's great Organ Fugue in E minor,

 \relative e' { \key e \minor \time 4/4 \partial 4 e4 | dis8 fis dis fis d gis d gis cis a' cis, a' c, ais' c, ais' | b,4 b' a8 g fis e | fis1 | e4 }

228. In both the cases. just referred to, the episode is of a more florid character than the subject of the fugue. In the great fugue which forms the finale of Beethoven's Sonata, Op. 106, the theme of which commences thus—

\relative f { \key bes \major \time 3/4 f8 r \afterGrace a'2\trill { g32[ a] } | bes4 r8 bes16 a g f ees d | g4 r8 g16 f ees d c bes | ees4 r8 ees16 d c d c bes }

we find an example of a different kind. Here is an episode in the key of D major, which itself begins like the exposition of a fugue—

Beethoven. Sonata, Op. 106.

\new ChoirStaff << \override Score.Rest #'style = #'classical \override Score.BarNumber #'break-visibility = #'#(#f #f #f)
  \new Staff \relative a' { \key d \major \time 3/4 \mark \markup \tiny { (\italic"a") } <<
    { r4 a^\( g | fis g a | d, e fis | g2 fis4 | e2 \)
      a4 ^~ a2. | b4 c d! | a g fis } \\
    { R2._\markup \italic "Dolce e cantabile." R |
      r4 d_\( c | b cis \) d _~ d cis2 |
      dis4 e fis | fis e d! _~ d e a,_"&c." } >> }
  \new Staff \relative a { \clef bass \key d \major
    R2.*4 r4 a^\( g | fis g a \) ^~ | a g fis | b cis, d } >>

After this episode has been developed for 29 bars, Beethoven combines it with the first part of the subject of the fugue in the following manner—

 %based on the accidentals in the second line, assuming that D major is incorrect for that line
\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.TimeSignature #'stencil = ##f \override Score.Rest #'style = #'classical
  \new Staff \relative c'' { \key bes \major \time 3/4 \mark \markup \tiny { (\italic"b") } <<
    { c8 r f4 ees | d ees f | b, c d | d, r r |
      R2. | r4 c'^\( bes a\) } \\
    { s4 \afterGrace a2_\trill { g32 a } |
      bes4 r8 bes16 a g f ees d |
      g4 r8 g16 f ees d c b | b'8 r g4_\( f |
      e f g | c, d e | f\) s_"&c." } >> }
  \new Staff \relative f { \clef bass \key bes \major <<
    { f4 c f, | bes r r | R2. \stemNeutral
      g4 \afterGrace b'2\trill { a32 b } |
      c4 r8 c16 bes a g f e |
      a4 r8 a16 g f e d c | f4 s } \\
    { a,4 } >> } >>

It looks at first sight as if there were here a double fugue (§ 175), with an independent exposition of its second subject. That this is not really so, is shown by the fact that the episodical theme does not subsequently appear regularly as a counterpoint to the subject.

229. Sometimes in the same fugue some of the episodes will be made from material already used, while others will be constructed of entirely new matter. An excellent example of this will be met with in the 37th fugue of the 'Wohltemperirtes Clavier.' We have already quoted the subject and countersubject of this fugue at § 162 (b). There are altogether four episodes. Of these the first and third were quoted in § 256 of Double Counterpoint, as an example of triple counterpoint in all its possible positions. The second episode is made from a sequential treatment of the countersubject, and the fourth is a transposition of the second, with inversion of the upper parts. This is often met with: for instance, in the two-part fugue in E minor (No. 10 of the 'Wohltemperirtes Clavier') there are four episodes, of which the third is an inversion of the first, and the fourth of the second.

230. We could multiply examples to any extent, and have, in fact, noted far more for quotation than we have room to insert; but we have already given enough to allow us to deduce general principles from them as to the construction of episodes. The first, and one of the most important inferences to be drawn from our illustrations, is the essential part played by sequence in nearly all the episodes. If we were forced to restrict ourselves to giving the student only one rule in this matter, we should select, as the most valuable we could give him, "Construct your episodes sequentially." Sequences not only furnish a very easy and simple means of modulation, but they combine variety of detail with unity of design in a degree which perhaps no other artistic device can attain. It is not necessary that the sequential imitations be at any regular distance. Sometimes they are so, as in our examples to §§ 222, 223; at other times, as in the second part of our quotation in § 225 (d), the distances of imitation are irregular.

231. Sequential treatment, important as it unquestionably is, is by no means the only point to consider with regard to episodes. A no less necessary requisite is variety. Each episode must have some feature which has not been seen in any of the preceding episodes. A mere transposition of one episode into a different key will be invariably weak and bad if no modification be made. On the other hand, some of the best episodes are made by repetition of an earlier episode with inversion of _parts. This gives the requisite variety, and at the same time preserves the artistic unity.

232. Beyond these general principles, it is impossible to teach the student how to write episodes for his fugues, excepting by showing him how the great masters have written them. It is here (just as with the "free fantasia" of a sonata or symphony) that the composer's imagination has the fullest scope. So long as he keeps within the bounds of the artistic and beautiful, he may in this part of the fugue do whatever seems good in his own eyes; and it will be in this part of the work, more than in any other, that his originality (if he have any) will be likely to assert itself.

233. Besides its use for the purposes of modulation, the episode serves, as already said, to separate the different groups of entries, or isolated entries, of the subject. We shall see, when we come to treat of the middle section of a fugue (Chap. IX.), that there is no restriction as to the number of these middle entries. Sometimes they are very few, at other times they are numerous. Consequently we find great differences as to the number of episodes in different fugues. For example, in the 'Wohltemperirtes Clavier' the 31st fugue has only one episode, and the 16th only two; but the 3rd, 12th, and 15th have six each. The number will depend entirely on the number of middle entries.

234. The length of the episodes is as variable as their number. In the majority of fugues they are comparatively short—often only two or three bars each; and in many cases it is better not to have too long an interval between the different entries of the subject. But they are occasionally found of considerable length. For instance, of the six episodes in the fugue in C sharp major (No. 3 of the 'Wohltemperirtes Clavier'), the first four and the last do not exceed four bars in length, but the fifth extends to fourteen bars. In the F major fugue (No. 35 of the same work) is seen a very unusually long episode of 28 bars. This, however, is quite an exceptional case. The composer's feeling of proportion and balance must be his guide in deciding both on the number and length of his episodes.

235. Occasionally, though very rarely in modern music, we find fugues without episodes. Such fugues were more frequently written, and more highly esteemed, by the old contrapuntists than they are at the present day. There is always danger of monotony if there are no episodes; even the first fugue of the 'Wohltemperirtes Clavier'—perhaps the finest fugue without episodes ever written—is from a purely musical point of view somewhat inferior in interest and charm to many others in the same collection.

236. As it is only by actual working, and not by any amount of mere verbal instruction that fugal composition can be learned, we shall now practically illustrate the directions given in this chapter by writing a series of episodes suitable to follow the expositions given in the last chapter—in three parts in § 194, and in four parts in § 204. They are both in the key of D major; and we will assume that the next appearance of the subject is to be in B minor, which is one of the most probable keys for the next entry. Our exposition ended in A major, from which key a modulation to B minor is perfectly easy, either direct or touching on D major first. In each of the episodes we give, we shall make use of material found in the exposition. We shall write all our examples in open score, that the student may be able to follow more easily the progression of the different voices; and we strongly advise him to follow the same plan in all his fugal exercises.

237. We first write some episodes to follow the three-part exposition in § 194, and in each case begin by completing the unfinished bar at the end.

\new ChoirStaff << \override Score.TimeSignature #'stencil = ##f \override Score.BarNumber #'break-visibility = #'#(#f #f #f)
  \new Staff \relative d'' { \key d \major \time 4/4
    d8 cis b4 a r8 e'16 d | cis8 b a4 g r8 d'16 cis |
    b8 a g4 fis8 fis16 gis ais8 gis16 ais | b8^"CS" d4 cis s8 }
  \new Staff \relative a' { \clef alto \key d \major
    a8 e ~ e16 fis e d cis d b cis a e' fis gis |
    a8 r r fis16 e d8 cis b d |
    g r r e16 d cis8 b cis r | b4^"S" e d }
  \new Staff \relative f { \clef bass \key d \major
    fis16 gis a4 gis8 a e a, r |
    r e''16 d cis8 d16 cis b8 a g4 |
    r8 d'16 cis b8 cis16 b ais8 gis fis e |
    d cis16 b ais fis gis ais s4 } >>

In this passage, the last half of the subject is treated sequentially in the treble, and accompanied by imitative counterpoint in the other two voices.

238. For our next episode

\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.TimeSignature #'stencil = ##f \override Score.Rest #'style = #'classical
  \new Staff \relative d'' { \key d \major \time 4/4
    d8 cis b4 a8 r r4 | r4*1/2 a16 b cis8 d e4 r |
    r8 b16 cis d8 e fis16 g fis e d e d cis | b8^"CS" d4 cis s8 }
  \new Staff \relative a' { \clef alto \key d \major
    a8 e ~ e16 fis e d cis8 d16 e fis8 g | a4 r r8 e16 fis g8 a |
    b4 r r2 | b,4^"S" e d }
  \new Staff \relative f { \clef bass \key d \major
    fis16 gis a4 gis8 a16 b a g fis g fis e |
    d fis e d cis d cis b a cis' b a g a g fis |
    e g fis e d e d cis b8 d16 e fis8 e |
    d8 cis16 b ais fis gis ais s4 } >>
we take the codetta in the second bar, which precedes the entrance of the answer, treat it sequentially, with imitation in the fifth above between the two upper parts, and accompany it in the bass with a semiquaver figure, developed from the figure
\relative d'' { \override Score.TimeSignature #'stencil = ##f \override Score.Clef #'stencil = ##f d16 e d c }
the second crotchet of the first bar of the alto part.

239. In both the above episodes we have returned from A to D, before going into B minor. In our last example in three parts we will make the modulation direct.

\new ChoirStaff << \override Score.TimeSignature #'stencil = ##f \override Score.Rest #'style = #'classical \override Score.BarNumber #'break-visibility = #'#(#f #f #f)
  \new Staff \relative d'' { \key d \major \time 4/4
    d8 cis b4 a8 cis4 b8 ~ | b a16 gis a8 cis b d4 cis8 ~ |
    cis b16 ais b8 d cis e4 d8 |
    cis g'4 fis8 eis e d cis | b^"CS" d4 cis s8 }
  \new Staff \relative a' { \clef alto \key d \major
    a8 e ~ e16 fis e d cis d e fis e fis d e |
    cis8 e r4 d16 e fis g! fis g e fis |
    d8. cis16 b8 fis' g16 fis e d cis ais b d |
    e d e fis g a b a gis d' cis g fis b ais e |
    d8 e16 fis g fis a g s4 }
  \new Staff \relative f { \clef bass \key d \major
    fis16 gis a4 gis8 a r r4 | a,16 b cis d cis b a cis d8 b r4 |
    b16 cis d e d cis b d e8 r r4 | R1 | b4^"S" e d } >>

This episode is made from the first part of the countersubject, which is accompanied by a new semiquaver figure in the alto, freely imitated in the tenth below by the bass.

240. We now give some episodes suitable for our four-part exposition. Although in actual practice, it is neither necessary nor expedient that all the episodes of a four-part fugue should be in four-part harmony, yet, as the episodes we are now writing are simply meant as illustrations of the method of composition, and as our previous examples have been in three parts, we will write these in four. As before, we begin by completing the last bar of the exposition.

\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.Rest #'style = #'classical \override Score.TimeSignature #'stencil = ##f
  \new Staff \relative d'' { \key d \major \time 4/4
    d8 cis b4 a r8 e' | fis e16 d cis d b cis d8 r r4 |
    g8 fis16 e dis e cis dis e8 r r4 |
    a8 gis16 fis eis fis dis eis fis8 cis ais4 | s2. }
  \new Staff \relative f' { \clef alto \key d \major
    fis16 gis a8 e b' e,16 fis e d cis d cis b |
    a8 r r4 a'8 a16 g fis g e fis |
    g8 r r4 b8 b16 a gis a fis gis |
    a4 r r2 | b,4^"S" e d_"&c." }
  \new Staff \relative b { \clef tenor \key d \major
    b8 cis16 d e fis d e cis d cis b a b a g |
    fis8 r r4 d' a | b r e b | cis r fis cis | s2. }
  \new Staff \relative a { \clef bass \key d \major
    a4 ~ a16 gis fis gis a8 a, b cis | d4 g fis r |
    e a gis r | fis b ais8 ais16 gis fis g e fis |
    d8^"CS" e16 fis g8 a b4 } >>

This episode is founded on the first three notes of the subject, treated sequentially in the bass, imitated by inverse movement in the tenor, and accompanied by a semiquaver figure in the upper voices, which is an imitation, partly inverted and partly direct, of the tenor part in the first half bar of the passage.

241. We not infrequently find in fugues that an episode is founded, not on subject or countersubject, but on one of the incidental counterpoints. To illustrate this, we construct our next episode in this way.

\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.Rest #'style = #'classical \override Score.TimeSignature #'stencil = ##f
  \new Staff \relative d'' { \key d \major \time 4/4
    d8 cis b4 a16 cis d e fis e d cis |
    b8 cis16 d e d cis b a8 b16 cis d cis b a |
    g8 a16 b cis b a g fis8 b4 ais8 | b4 cis d r | s }
  \new Staff \relative f' { \clef alto \key d \major
    fis16 gis a8 e b' e, r r4 | d8 e16 fis g8 r cis, d16 e fis8 r |
    b,8 cis16 d e8 r ais, fis' e16 d fis e |
    d8^"CS" e16 fis g8 a b fis b4( | s)_"&c." }
  \new Staff \relative b { \clef tenor \key d \major
    b8 cis16 d e fis d e cis8 r cis d16 e |
    fis8 r b, cis16 d e8 r a, b16 cis |
    d8 r g, a16 b cis8 r r4 | b^"S" e d r8 g16 fis | s4 }
  \new Staff \relative a { \clef bass \key d \major
    a4 ~ a16 gis fis gis a8 e a4 ~ | a g2 fis4 ~ |
    fis e ~ e8 d cis fis | b,4 r r8 b'16 a g fis e d | s4 } >>

The sequence here seen in the treble is founded on the figure employed in the tenor in the second half of the seventh bar of the exposition in § 204. It is accompanied by a sequence in the tenor, formed from the beginning of the countersubject, and imitated in the second above, and at one crotchet's distance by the alto.

242. Our last episode is more elaborate, and is given to illustrate the incidental employment of canon in fugal writing.

\new ChoirStaff << \override Score.BarNumber #'break-visibility = #'#(#f #f #f) \override Score.Rest #'style = #'classical \override Score.TimeSignature #'stencil = ##f
  \new Staff \relative d'' { \key d \major \time 4/4
    d8 cis b4 a r | r8 fis' ~ fis16 e e d cis4 r |
    r8 g' ~ g16 fis fis e d4 r |
    r cis8 cis16 d e8 e16 fis g8 ais, | s1 }
  \new Staff \relative f' { \clef alto \key d \major
    fis16 gis a8 e b' e,16 fis e d cis e cis b |
    a8 d16 e fis8 g a e a4 | e8 e16 fis g8 a b fis b4 |
    fis8 fis16 gis ais4 r2 | b,4^"S" e d r8 g16 fis }
  \new Staff \relative b { \clef tenor \key d \major
    b8 cis16 d e fis d e cis d cis b a b a g |
    fis8 r r4 a8 a16 b cis8 d | e b e4 b8 b16 cis d8 e |
    fis cis fis4 cis8 cis16 d e8 cis | s1 }
  \new Staff \relative a { \clef bass \key d \major
    a4 ~ a16 gis fis gis a8 a, b cis |
    d8 r r4 r8 a' ~ a16 g g fis | e4 r r8 b' ~ b16 a a g |
    fis4 r e8 e16 d cis8 fis16 e | d8^"CS" e16 fis g8 a b fis b4 } >>

In the second bar of this passage the first bar of the countersubject is introduced in the alto, and treated sequentially in the following bar. It is also accompanied by a sequential counterpoint. Both these parts are imitated by the tenor and bass, making a "4 in 2" canon; but the inversion of the voices, instead of being, as usual, in the octave, is in the tenth, thus giving a somewhat rare combination of canon and double counterpoint in the tenth. In the last bar of the episode, the canon is abandoned, and we have merely ordinary imitation, direct and inverted, of a fragment of the countersubject.

243. These examples will show the student how much variety of episode is possible, even with such commonplace subjects as we have been treating here. He will now see clearly what we meant when in Double Counterpoint (§ 307) we spoke of Imitation as "a most important ingredient" in fugues. In fact, imitation and sequence are the chief essentials of good episodes. Let the student now turn back to the expositions he has written as exercises on the last chapter, and utilize his material (subjects, countersubjects, codettas, and incidental counterpoints) for the construction of many different episodes, after the manner which we have shown him in this chapter. He should write five or six episodes for each fugue, varying the keys to which he modulates. For the present he should not go beyond the nearly related keys.