1. 曲式分析
Form and Analysis

2. Fugue
Historical note
Fuga was first used by Jacobus of Liege (c. 1330)
Synonymous with rindellus or rota
15th & 16th century, composers frequently made great use of fugal procedure in their sacred and secular works---the masses, motet and chanson.
In 16th century, the motet and chanson were models for similar instrumental genres, the ricercari, canzon da sonar.
The ricercar was solemn in character, and the canzona was rhythmic and lively, less rigidly contrapuntal. The two styles persisted in the writing of 18th century
Bach WTC: C major; C minor

3. Fugue Fugue and form The fugue is not a form.
two Bach fugues may have much in common
Exhibit texture similar contrapuntal procedures.
Beethoven came rely more and more on the fugue as a means of artistic expression.

4. Fugue Characteristics of Fugue
Polyphonic composition with a texture made up of a constant number of melodic lines, three or four. Vocal terminology for those lines: soprano, alto, tenor, bass.
The fugue is base on a theme begin in one voice, is imitated by another, again by a third, and so on, until each voice has state it.
The theme is called subject, its imitation the answer

5. Fugue Subject and Answer Two types of imitation: real; tonal
Handel Messiah, Part II
Subject: (5-1, 3-6, 1-4)
Answer: (1-5, 7-3, 5-1)
1. Regarding imitation: as it enters, each voice sounds either 1 or 5 of the main tonality
2. The answering voice transposes the subject up a perfect fifth or down a perfect fourth

6. Fugue Subject and Answer Bach: WTC, No. 2 Subject: () Answer: ()
3. A prominent 5 near the beginning of the subject is answered by 1, not by 2

7. Fugue Subject and Answer Bach WTC, Fugue in C Subject: (1234543625)
4. If the subject does not stress 5, the answer is a real imitation at the upper fifth or, at the lower fourth.

8. Fugue Subject with the 7th scale degree Bach WTC, Fugue in A Subject:
Answer:
5. Transposed up a fifth, a 7 in the subject need not answered by 4-a fifth above-but by 3.

9. Fugue Subject with a secondary tonic Bach : Magnifat, No 11 Subject:
Answer:
Delayed ascend

10. Fugue Method for Answer of a fugue subject
Examine the subject and note whether it exhibits a. an initial 5, b. use V as secondary tonic (#4-5), or a conspicuous 7 near the beginning
If none of these condition exists, one has merely to answer with real imitation: transpose the subject a perfect fifth higher.

11. Contrapuntal devices in fugue
Fugal procedure
Augmentation, diminution, inversion, retrograde
Stretto 提前進入
Stretto may occur at any time in the course of the fugue.
As a means of building up excitement and tension at some climactic point.
Invertible counterpoint
two melodic lines exchange places so that the line first appears in the lower position is put in the upper

12. Fugue Fugal procedure Bach: WTC, vol. 1, Fugue No. 16
Subject: Two motives (m, n), alto
Tonal answer by soprano, alto counterpoint from two motives, when subject appears it is nearly always accompanied by this same counterpoint (countersubject)
One bar episode after soprano (motive n in sequence)
Subject in bass, followed by tenor answer.
One single exposition

13. Fugue Bach: WTC, vol. 1, Fugue No. 16 Exposition I, later expositions:
order of entry: A-S-B-T, episode seperates entries into two pairs
later expositions:
no standard arrangement of subject and answer version
No fixed number of entries
Sometimes entire theme is not stated, final or first note are diverted
Episode I, II, III:
without sacrificing their value as relief from the subject, episode are motivic related to it
Over all
Only a few passages do all four voices sound at once. Most of the time one of them is silent. Final entry in five voices.
The piece consists of five expositions and five episodes
Rely heavily on inversion, double counterpoint, and stretto

14. Fugue
Observation
No preferred order for entry for the voice. “High” voice begins, then it is a “low” voice which will answer, and vice versa.
Subject and answer versions of the theme alternate, but exceptions occur.
Fugues have been written without episodes (WTC, No. 1)
All kind of contrapuntal devices may be used

15. Fugue
Tonal structure
i -> ii V I/of III -> iv -> ii0 V i -> ii0 V i

16. Design Pachebel No any striking contrast to the exp.
Episodes: ne new mood or emotional quality or basic rhythmic structure
Lightening texture; omission of references to the fugue theme

17. Design Part I Part II Part III Ex. I Ep. 1 (cont.) Ep. 2 Ex. II Ep. 3
Ex. III
Ep. 4
Ex. IV
Ep. 5
Ex. V A B C A’ B’ A” C’
A’” B”
A””
i  ii V I// III
III  iv ii0 V i
i  ii0 V i

18. Special Types of Fugue Fugues in contrary motion
Bach: Art of Fugue: Contrapuntus V; Score
Contrapuntus V; Score

19. Types of Fugue
Handel: concerto grosso op. 6, no. 7,
Allegro (29’17”)

20. Special Types of Fugue Invertible Fugues (mirror fugue)
Bach: Art of Fugue: Contrapuntus XII; XIII
Rectus; Inversus

21. Special Types of Fugue
Bach: Art of Fugue

22. Special Types of Fugue Double Fugue Bach: Art of Fugue: IX
Mozart: Requiem, Kyrie; Score

23. Special Types of Fugue Triple Fugue
Beethoven, Symphony No. 9, I; development
Bach: Art of Fugue:
VIII; Score: several parts, part one simple fugue, part two SUBJECT II (m. 39), Subject III (mm, ), part two ends (m.124); part three three subjects are combine in m. 147.
XI; Score: part one simple fugue; part two simple fugue of subject II; part three inversion of subject I; part four
WTC I, No. 14; WTC I, No. 24; WTC I, 19 prelude

24. Special Types of Fugue Fugue with uncertain classification
A subject is accompanied throughout the fugue with a distinctive countersubject, might not that the countrsubjct be considered in essence a second subject?
Not to regard a consistantly recurring countersubject as a second or third subject. In a double fugue the listening is forcibly made aware of the presence of the subject II
Bach: Art of Fugue:
VIII; Score: several parts, part one simple fugue, part two SUBJECT II (m. 39), Subject III (mm, ), part two ends (m.124); part three three subjects are combine in m. 147.
XI; Score: part one simple fugue; part two simple fugue of subject II; part three inversion of subject I; part four
WTC I, No. 14; WTC I, No. 24; WTC I, 19 prelude

25. The Invention
The thirty short pieces of J. S. Bach which we refer today as the two- and three- part invention are similar in some ways to the fugue
Both are polyphonic compisitions
Both are based on a single theme, normally stated by each voice,
Both are imitative counterpoint
Make frequent use of contrapuntal devices such as inversion
Both are contrapuntal procedures rather than form

26. The Invention The chief differences are as follows.
Fugue subject are answer at the fifth above.
The initial statements of the subject of the fugues are unaccompanied. (except for those intended for ensemble)
Very short themes, hardly more than motives, are common in the inventions.
The fugue is an instrumental or vocal genre; the invention is for keyboard.
Prelude No. 3, Invention No. 1; No. 4; No. 15

27. French Overture
17th century Opera overtre, consit in two parts, a slow part follows by a fast one; the second part begins with imitation invarious voices, a partially fugal texture rather than a real fugue.
Handel: Messiah
Bach: Suite No. 2