Bach: Prelude and Fugue No.15 in G major, BWV 884 Analysis



Bach Prelude and Fugue No.15 in G major BWV 884 Analysis 1


This Prelude is constructed upon the following figure seen above.

Bars 1-16: Period I. Tonic Pedal in the Bass part, with the Dominant Pedal reiterated in semiquavers (sixteenth notes) in the Treble part (Bars 1-3). Dominant Pedal in the Treble part, with Supertonic Pedal in the Tenor part (Bars 4-7). Ending with a Perfect Cadence in the key of the Dominant, D; double bar.

Bars 17-48: Period II. Dominant Pedal in the Bass part, with the same reiterated in the Alto part (Bars 17-19). Tonic Pedal in the Bass part (Bars 20-22). Ending with a Perfect Cadence in the key of the Tonic, G.


This Prelude is divided into two parts by the double bar.

It affords examples of the employment of double Pedals, one being sustained, the other reiterated in semiquavers (sixteenth notes).

At Bars 4-6, the material of Bars 1-3 is transposed into the key of the Dominant, the three figures of which it is composed being placed in different parts, thus securing variety.

Exactly the same system of structure is noticeable at the beginning of the Second part of the movement as at the first; Bars 17-20 being transposed and used again in Bars 20-23.

Bars 43-48 are a transposition into the key of the Tonic of the material previously employed at Bars 11-16 in the key of the Dominant, a slight alteration only being made in the Bass part (Bars 43-44).

Period I has no marked subdivision, but Period II subdivides at Bar 28, where there is a Perfect Cadence in the key of the Relative Minor (E), and also at Bar 32, where there is a Perfect Cadence to the Subdominant Major (C).

The “form” of this Prelude is that of the early Binary type, of which it is an obvious example. Moreover, the emphasis laid upon the complementary key – the Dominant – as the latter portion of the first part of the movement (Bars 11 and onwards), may be regarded by analogy as supplying the place of th Second Subject in that key; and the material used here is transposed into the Tonic key in the second part of the movement (Bar 43 to the end). The part immediately following the double bar is a slightly modified version in the key of the Dominant of the Opening bars. The last seven bars being a transposition into the Tonic of material used in the corresponding place in the Dominant in the first part of the movement, play in important part in the unification of the whole.



Bach Prelude and Fugue No.15 in G major BWV 884 Analysis 2



Bars 1-6: Subject in Treble [G major].
Bars 6-8: Codetta, modulating from G to D.
Bars 8-13: Tonal Answer in Alto. No Counter-subject.
Bars 13-14: Codetta, modulating from D to G.
Bars 15-20: Subject in Bass [G major].
Bars 20-23: Codetta, modulating from G to D; close in D.


Bars 23-33: Episode I, modulating from D, through G major, A minor, to E minor.
Bars 33-38: Subject in Bass [E minor].
Bars 38-40: Codetta, modulating from E minor to B minor.
Bars 40-45: Answer in Treble [B minor].
Bars 45-65: Episode II, modulating from B minor to G major.


Bars 65-70: Subject in Alto [G major].
Bars 70-72: Coda [G major].


Exposition: Bars 1-20.
Counter-exposition: None.
Codettas: Four.
Stretti: None.
Episodes: Two.
Dominant Pedal: Bars 56-61.
Coda: Bars 70-72.


  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 note to the second.
  2. The Codettas are of great importance in this Fugue for modulatory purposes, paving the way for the entry of the Subject and Answer.
  3. This Fugue is of an Instrumental character, which accounts for its assuming such an extensive compass in its latter portion.
  4. At Bar 62 a Bravura passage in scale form is started in the Bass and rises through three octaves, leading to the Recapitulation of the Subject in Bar 65.
  5. Episode I (Bar 23) is formed mainly from the first two bars of the Subject, the Bass proposing the figure in the key of D, Bar 23 (at which key the third Codetta has landed it). This is freely imitated by the Treble at two bars’ distance, the Alto being formed of a detached figure with the addition of suspensions.
  6. Episode II (Bar 45) is formed upon the second bar of the Subject, the Imitation starting with the Treble and working downwards through the Alto and Bass.