Bach: Prelude and Fugue No.23 in B major, BWV 868 Analysis

Analysis

Prelude

Bach Prelude and Fugue No.23 in B major BWV 868 Analysis 1

SUMMARY:

Bars 1-6: Period I. Tonic Pedal (Bars 1-3). Ending with a Perfect Cadence in the key of the Dominant.

Bars 6-10: Period II. Ending with a Perfect Cadence in the key of the Submediant.

Bars 10-15: Period III. Ending with a Perfect Cadence in the key of the Tonic.

Bars 15-19: Period IV. Coda. Dominant Pedal (Bars 17,18).

REMARKS:

This Prelude is constructed upon the figures which appear in Bar 1, that in the Treble being used most frequently.

In Bar 6 the figures of Bar 1 are reproduced in the key of the Dominant, but the Treble of the former becomes the Bass of the latter, and vice versa.

Bar 12 is a descending Sequence with Bar 11.

The following list furnishes every instance of the Principle Theme used in its inverted form:

  1. In the Bass part at Bar 12.
  2. In the Treble part at Bar 15.
  3. In the Treble part at Bar 16.
  4. In the Tenor part at Bar 17.
  5. In the Treble part at Bar 18.
  6. In the Alto part at Bar 18.

 

Fugue

Bach Prelude and Fugue No.23 in B major BWV 868 Analysis 2

ANALYSIS:

ENUNCIATION SECTION:

Bars 1-3: Subject in Tenor [B major].
Bars 3-5: Tonal Answer in Alto [F sharp major].
Bars 3-4: Counter-subject in Tenor.
Bars 5-7: Subject in Treble. Counter-subject in Alto [B major].
Bars 7-9: Answer in Bass. Counter-subject in Treble [F sharp major].
Bars 9-11: Codetta formed to a limited extent from the fist part of the Counter-subject.
Bars 11-13: Subject in Tenor [B major].

MODULATORY SECTION:

Bars 13-16: Episode I, modulating from B to F sharp.
Bars 16-17: Subject in Alto and Close in F sharp (Dominant) [F sharp major].
Bars 18-20: Subject my Inversion in Treble [F sharp major].
Bars 20-22: Answer by Inversion in Alto [F sharp major].
Bars 21-23: Subject in Bass [B major].
Bars 24-26: Answer in Tenor and Close in C sharp minor [C sharp minor].
Bars 26-29: Episode II, modulating form C sharp minor to B major.

RECAPITULATORY SECTION:

Bars 29-31: Subject in Alto [B major].
Bars 31-33: Answer in Treble. Counter-subject in Alto [F sharp major].
Bars 33-34: Coda [B major].
Bars 33-34: Reminiscences of first few notes of Counter-subject in Tenor [B major].

SUMMARY:

Exposition: Bars 1-9.
Counter-exposition: None.
Episodes: Two.
Stretti: None.
Pedal: None.
Coda: Bars 33-34.

REMARKS:

  1. This Fugue has a “tonal” Answer, and would be called a “tonal” Fugue. The alteration in the Answer, for the sake of tonality, is made from the first to the second and from the fifth to the sixth notes.
  2. After the Exposition the Counter-subject is only used once in its entirety, and that near the end of the movement (Bars 31-33). On two occasions (Bar 12 in the Alto and Bar 17 in the Treble) its second half only is used.  On two occasions (Bar 12 in the Alto and Bar 17 in the Treble) its second half only is used. On other occasions it is absent.
  3. The Episodes are constructed upon the first part of the Counter-subject, though only to a limited extent. At Bars 14-15 its first limb appears in the Tenor, and Bars 26-27 it appears in the Bass. In the Coda there occurs a reminiscence of the last part of the Counter-subject in the Treble and of the first part in the Tenor (Bar 33).