One lesson learned from studying the Well-Tempered Clavier is that there is no such thing as a single model for Bach’s fugal construction. There may be underlying uniformities in voice leading and harmonic paradigms, but each fugue ultimately differs from its siblings in quite essential ways be- cause each grows rhetorically from the idiosyncratic interaction of its unique subject and structural principles. For instance, the two fugues in C in vol. 1 may both present their subject or its motives persistently, but each does this in totally different ways. Bach’s creativity is endlessly inventive. The same is true of the two other solo-violin fugues as they relate to that in G minor. For instance, the subjects of the G-minor and A-minor fugues may be of identical length and metric position, and both may start on 5ˆ and end on 3ˆ . But far more important to their individual structures is that the G-minor subject is narrow in range, features iteration or step- wise motion (except for one skip by a third), and demands a unique sub- dominant answer, while the A-minor subject ranges over an octave with mostly skips and has a usual tonal answer.
In general, the A-minor Fuga looks quite similar to the G-minor, with its short subject, its eighths and pairs of sixteenths during subject statements that contrast with measures of sixteenths during episodes, and its occa- sional grand cadences that articulate the flow (in m. 45 in A minor, m. 73 in E minor, m. 103 in C major, m. 137 in E minor, m. 166 in G major, m. 232 in D minor, and mm. 280 and 289 in A minor). But it is over 50 percent longer (289 measures of 2/4 versus 94 of 4/4 in the G-minor Fuga) and marks its larger structural shape with different contrapuntal devices. The opening few measures introduce three separate ideas that interact through- out: the subject, and the episodic figure, and its chromatic-scale counter- point in mm. 5– 6. These ideas intertwine in increasingly complex ways, and each idea appears inverted after m. 125, with frequent references to earlier passages. A single instance of many is the chordal statement of the subject in the bass that begins on G in m. 91 with the descending chromatic scale above; beginning in m. 162, this passage recurs recomposed into an- other chordal statement of the subject that also begins on G, this time in the soprano, with the chromatic scale — but now ascending — in the bass. Both of these passages are chromatic intensifications of a fully diatonic chordal statement of the subject, also beginning on G, in mm. 81.
The C-major Fuga is quite different, with its considerably longer sub- ject, overall length, and design. Yet like the A-minor Fuga, it works with the subject and its inversion (whose first appearance Bach marks with the words al riverso) and a chromatic-scale countersubject that also appears inverted only when the inversion of the subject enters. The C-major Fuga concludes by bringing back its first 66 measures in da capo fashion — a fugal procedure absent from the other violin fugues and the Well-Tempered but present in the fugal preludes to Bach’s English Suites 2– 6.
Example 3-19. (a) “An Wasserflüssen Babylon,” opening phrase, as in Albert Riemenschneider, 371 Harmonized Chorales by Johann Sebastian Bach (New York: Schirmer, 1941), no. 5; (b) Bach, Sonata in C Major, Fuga, mm. 108; (c) fugue subject from Mattheson, Grosse Generalbassschule, p. 36; (d) opening of a fugue exposition from Mattheson, Der vollkommene Capellmeister, part 3, chapter 20, ¶ 16. a.
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& c
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b.& C
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== B
w
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w
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fugue that Bach performed when he applied for a job in Hamburg in De- cember of 1720, the year in which he wrote the autograph score of the solo-violin works.13 That organ performance in Hamburg led to one of
the most famous tributes Bach ever received. In the audience was the 97- year-old organist and composer Johann Adam Reinken (1623–1722), whose playing Bach had admired quite a few years earlier. Among the music that Bach played as part of his audition was a long improvisation on the chorale melody “An Wasserflüssen Babylon” (“By the Streams of Babylon”). As Forkel recounts in his 1802 biography, Bach was fond of improvising in this manner “in all the various forms of organ composition. . . . First, he used this theme for a prelude and a fugue. . . . Finally, [after a trio or quartet and an elaborate version of the chorale] the conclusion was made by a fugue.”14 Reinken, much taken with Bach’s improvisation,
told him, “I thought that this art was dead, but I see that in you it still lives.”15
The beginning of the chorale melody “An Wasserflüssen Babylon” is close to Bach’s fugue subject in the C-major solo sonata, as shown in Ex- ample 3-19a. (The fugue subject melody is often associated with the chorale melody “Komm heiliger Geist, Herre Gott,” which is identical with the melody to “An Wasserflüssen Babylon” for the first seven notes.) This
alone would suggest that Bach performed something like an organ version of his violin fugue in Hamburg. Further circumstantial evidence comes from Johann Mattheson, the Hamburg composer, theorist, and chronicler of musical life who was present at Bach’s performance and who in 1728 published an anonymous account of Bach’s application for the Hamburg position.16 In 1731, Mattheson included in his Grosse Generalbassschule
(Large Thoroughbass School) the fugue subject in Example 3-19c.17 And
in his Vollkommener Capellmeister (Complete Capellmeister) just a few years later, he included the fugue subject as Bach wrote it along with a countersubject almost identical to Bach’s, as shown in Example 3-19d.18
Moser hypothesizes that when Mattheson first wrote out the subject in 1731 he was writing it down as he remembered it from Bach’s perfor- mance in 1720, but by the time he prepared his Vollkommener Capellmei-
ster he had seen a copy of the violin version of the fugue and therefore
wrote it down in a form closer to how it appears in Bach’s C-major solo sonata.19 But if that were the case, Mattheson would have written the sub-
ject and answer out in C major, not in G. In fact, Bach never places the subject and answer together in this manner in the C-major Fuga, although the disposition of subject and answer that Mattheson illustrates is an al- most exact inversion of the opening subject and answer of the violin Fuga.
It is more likely that Mattheson was copying the fugal exposition he il- lustrates in his Vollkommener Capellmeister from a G-major keyboard ver- sion of the violin fugue. Supporting this contention is the early-eighteenth- century keyboard version (cited in chapter 2) of the Adagio of the C-major Sonata — in G major (BWV 968). Perhaps this movement is the extant portion of a keyboard arrangement of at least the Adagio and Fuga of the C-major solo sonata, akin to the keyboard arrangement of the entire A- minor solo sonata in D minor (BWV 964) and the organ arrangement of the G-minor Fuga. In any case, if Bach in December of 1720 did perform an organ version of this fugue in Hamburg, was he perhaps not improvis- ing, as Reinken supposed, but simply performing the fugue he had so care- fully composed for the solo-violin sonata?