Bach: Prelude and Fugue No.6 in D minor, BWV 851 Analysis

Analysis

Prelude

Bach Prelude and Fugue No.6 in D minor BWV 851 Analysis 1

SUMMARY:

Bars 1-6: Period I. Tonic Pedal (Bars 1-2). Ending with Perfect Cadence in the Relative Major, F.

Bars 6-15: Period II. Ending with the Perfect Cadence in the Tonic Major, D.

Bars 15-26: Period III. Tonic Pedal (Bars 15-21), Dominant Pedal (Bar 23). Coda.

REMARKS:

In the early part of this Prelude the sequential character of some of its Phrases should be notes, for instance, Bars 6-8 are imitated by Bars 8-10 in an ascending Sequence. It is then broken for two bars, but re-appears in Bars 12-14.

Period II is Modulatory; its first Phrase, Bars 6-8, modulating to G minor (Subdominant), its second Phrase to A minor (Dominant), and so on, proceeding finally to the Tonic Major (Bar 15), where the Coda is commenced.

Fugue

Bach Prelude and Fugue No.6 in D minor BWV 851 Analysis 2

ANALYSIS:

ENUNCIATION SECTION:

Bars 1-3: Subject in Treble [Key: D].
Bars 3-5: Real Answer in Alto, with Counter-subject in Treble [Key: A].
Bars 5-6: Codetta, founded on Counter-subject.
Bars 6-8: Subject in Bass. First limb with counter-subject in Treble [Key: D].
Bars 7-8: Second limb of Counter-subject in Alto.

MODULATORY SECTION:

Bars 8-10:  Subject (irregular as to position) in Treble. Counter-subject in Bass [Key: D].
Bars 10-13: Episode I, modulating from D to A, forming a descending sequence.
Bars 12-13: Subject (fragment of) in Bass, the first note being altered (E flat instead of F). Answer in Alto (first five notes only) by Inversion [Key: D].
Bars 13-15: Subject in Treble. Counter-subject (first part only) in Bass [Key: A].
Bars 13-16: Stretto I (incomplete).
Bars 14-16: Answered by Inversion in Alto. Ascending sequential figure in the Bass in Bars 15-16.
Bars 17-20: Fragment of Counter-subject in Treble. Subject in Bass and Subject in Alto successively, in Stretto. Close in A in Bar 21 [Key: A].
Bars 21-23: Subject in Bass. Counter-subject in Treble [Key: A].
Bars 22-24: Answered by Inversion in Treble. Stretto III (incomplete) [Key: A].
Bars 23-25Subject by Inversion in Bass [Key: D].
Bars 24-25: Counter-subject in Treble.
Bars 25-27: Episode II, modulating from D minor to G minor.
Bars 26-27: Subject by Inversion in Bass [Key: G].
Bars 27-29: Answered by Inversion in Treble. Stretto IV (complete) [Key: A].
Bars 28-30: Subject in Alto.
Bars 29-31: Answered by Inversion in Bass, passing to G minor [Key: D].
Bars 31-33: Episode III, modulating from G minor to D minor by way of F.
Bars 33-34: Subject in Alto (incomplete) [Key: D].
Bars 34-36: Subject in Bass. Stretto V (incomplete) [Key: D].
Bars 36-39: Episode IV, modulating from G minor to D minor.

RECAPITULATORY SECTION:

Bars 39-41: Subject in Bass [Key: D].
Bars 40-42: Subject in Alto. Stretto VI (incomplete) [Key: D].
Bars 42-44: Coda [Key: D]
Bars 43-44: Pedal. Final chord major. Tierce de Picardie.

SUMMARY:

Exposition: Bars 1-8.
Counter-exposition: None.
Episodes: Four.
Stretti: Six, one being complete and five incomplete. The entries are all exactly at one bar’s distance from each other.
Free Inversion of the Subject and Answer: Several instances.
Coda: Bar 42-44.
Tonic Pedal: Bars 43-44.

REMARKS

  1. This Fugue has a “real” Answer, and would be called a “real” Fugue.
  2. The treatment of the Subject is remarkable on account of its frequent employment of the major instead of the minor third. After the Exposition the theme is used no less than eight times with the major third.
  3. This Fugue contains the device of Inversion of the Subject and Answer.
  4. At Bar 7 the Counter-subject is transferred from the Treble to the Alto, halfway through.
  5. The Episodes are constructed from material taken from the Counter-subject.
  6. On the Tonic Pedal, the Subject is used in the second and third voices by inversion, and at the same time by direct motion in the fourth and fifth voices (Bar 43), forming a succession of rich harmonies in six part, for the conclusion.