Prelude and Fugue in D Minor, BWV 851 from WTC I

Vidas Pinkevicius

Prelude

This Prelude is a toccata-like virtuosic piece with continuous arpeggiated right hand part which moves in sixteenth-note triplets. In contrast, the left hand usually is written in eighth-notes. The piece is 26 measures long and according to tonal areas can be divided into two parts: mm. 1-15 and 15-26. Proportionally, m. 15 can be considered as a turning point which is close to a halfway of the Prelude.

The first part of the Prelude is structured into three sections. In m. 1, Bach establishes the D minor key and in mm. 2 to 5 moves to the relative major key (F major) (Section I). In mm. 6 to 9, the composer forms two two-measure sequences in the key of G minor and A minor respectively (Section II). Measures 10 to 14 serve as a transitional episode leading back to D minor with short tonicisations to A minor, F major, D minor, B flat major and G minor (Section III). As a result, Section I has five measures, Section II – four, and Section III five measures which is proportionally close to 1/3 each of this first part.

The second part (mm.15 to 26) probably can be divided into two sections. Section I (mm. 23) is an extended D pedal point featuring interchange of diminished seventh chord of Subdominant (G minor) and G minor second inversion triad plus return to the Tonic. Significantly, until here, the harmonic rhythm was very intense, moving mostly in quarter notes or even in eighth notes. The harmonic rhythm of the D pedal point section, in contrast, changes to half measure which creates a sense of constant growing tension.

Interestingly, instead of closing the Prelude with the same perpetual motion in two parts, Bach chose to interrupt the flow with an unexpected change of texture (m. 24) which forms a Section II. In m. 24, the composer presents us brilliant chain of arpeggiated diminished triads which are written for the right hand without any support of the left hand. In this chain, Bach reaches b” (the highest note of the Prelude) which can be considered as a climactic point of the piece. The piece ends with a cadence in quarter-notes and full chord. Proportionally, Section I is 2/3 of the Part II (9 measures) and Section II – 1/3 of the Part II ( 3 measures).

Fugue

The fugue is written in three parts and has 44 measures. Besides the subject, the most important unifying material is taken from the countersubject which features two sets of sixteenth-notes. The subject itself starts with the series of rising eighth notes which can be considered as opposite to falling sixteenths of the countersubject. Moreover, both subject and countersubject feature one common figure – a leap of minor 6.

There are a total number of 16 subject entries (for a list of a detailed analysis of subject entries refer to Appendix 1). The exposition of the Fugue, which features subject in the soprano, answer in the tenor, and subject in the bass, ends in m. 8, which is followed by a subject in the Soprano from e’. This entry is important because it does not start from the D or A (like original subject and answer) but is still in D minor. Significantly, none of the subject entries throughout the Fugue are in the key other that D minor or A minor (most of the time the fugue is D minor).

The composer in this fugue shows his mastery in writing strettos. There are a total number of five strettos in the piece and the first one starts in m. 13 (for a list of a detailed analysis of strettos refer to Appendix 2).  Here Bach combines the original subject (soprano) and an inversion (tenor) after a time interval of three quarter notes at the interval of a lower fourth (interestingly, all five Strettos are for the same time interval). Stretto II is for the bass and the tenor (m. 21), at the octave. This stretto is important because it marks an exact halfway of the piece (1/2 proportion). Measures 22-23 feature a continuation of the same stretto with additional entry in the bass.

The only stretto in the fugue which is in three voices is Stretto IV (mm. 27-30). Here Bach writes the subject in the tenor and inversions in the soprano and the bass at the interval of a lower fifth and upper fourth. In m. 34, the composer writes altered subject in the bass which is followed by a rising sequence formed from inversions of incipits of the subject (mm. 36-38). In this sequence, one can sense rising tension and approaching final measures of the fugue. The fugue ends with Stretto V which is for the bass and tenor at the interval of an octave.

Overall, after examining the strettos, it is evident that Bach exhausts virtually every possibility of voice combinations, with the exception of tenor/soprano. However, even this combination can be sensed in m. 12, when Bach puts altered inverted version of the subject in the tenor after which follows Stretto I with the soprano entry.

Having analyzed the fugue, we will reveal the relationship between the Prelude and Fugue. This relationship can be loosely sensed in two ways. The first and perhaps the most obvious is that every arpeggiated figure of the Prelude ends with a leap which is also one of the features of the fugal subject and countersubject. The second possible relationship between the Prelude and the Fugue might be that the incipit of the fugal subject (notes D, E, F, G, and E) is foreshadowed in the beginning of the Prelude (See attached score).

In conclusion, in this Prelude and Fugue, Bach shows his mastery not only of a contrapuntal writing but also of harmonic language, which often features diminished seventh-chords and chromaticisms. This characteristic of Bach’s musical vocabulary makes his music sound so dramatic. In addition, the composer’s ability to control harmonic rhythm makes listener to experience constant change from tension to relief. Finally, Bach’s interest in proportions is evident from both Prelude and Fugue.

Appendix 1: Subject Entries

No.

Measure No.

Voice

Beginning Pitch

1

1

S

d’

2

3

T

A

3

6

B

D

4

8

S

E’

5

13

S

A’

6

14

T

e’ (inversion)

7

17

B

A

8

18

T

A

8

21

B

A

9

22

S

e’ (inversion)

10

23

B

F (inversion)

11

27

S

a” (inversion)

12

28

T

D’

13

29

B

a (inversion)

14

34

B

D

15

39

B

D

16

40

T

d’

Appendix 2: Stretto

No.

Measure No.

Voices

Pitch interval

Time interval

(in quarter notes)

Beginning pitch of the subject

(beginning pitch of the following entry)

1

13

ST (2v)

↓4

3

a’ (e’)

2

17

BT (2v)

↑8

3

A (a)

3

21-22

BSSB (2v)

↑5

↓7

3

3

A (e” inversion)

e” inversion (f inversion)

4

27-28

ST (3v)TB ↓5↓4

3

3

a” inversion (d’)

d’ (a inversion)

5

39

BT (2v) ↑8

3

d (d’)

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s