Bars 1-17: Period I. Ending with a Perfect Cadence in the key of the Relative Major, D.
Bars 17-41: Period II. Ending with a Perfect Cadence in the key of the Dominant Minor, F sharp.
Bars 41-57: Period III. Ending with a Half Cadence on the 1st Inversion of the Dominant 9th chord.
Bars 57-66: Period IV. Ending with a Perfect Cadence in the key of the Tonic, B.
This Prelude is built mainly upon four Themes, Themes I and II being braced together on two occasions (1) at the commencement, and (2) at Bars 17-20. The construction of these two Themes is also notable.
Theme III formed of three detached figures, first makes its appearance in Bar 5, being placed above Theme I, which was used in the upper part previously (Bars 1-4), but is now assigned to the Bass.
Theme IV first makes its appearance at Bar 8 (Treble part), and is chiefly used for Episodal work between the entries of the big Themes I and II.
At Bars 21-24 still another figure, built chiefly upon the ornament of the Turn, and being a sort of variation of Theme II inverted, appears placed above Theme I. Though this figure is only used on one other occasion (Bars 59-62), yet its position is important, being transposed into the Tonic key in the second part of the movement.
Bars 9-14 also appear in the second part of the movement transposed a fourth lower (Bars 45-50).
Sequential work is prominent in this Prelude, instances being Bars 9-17, 50-52 and 54-57.
Period I is capable of two subdivisions, (1) in the middle of Bar 4, and (2) in the middle of Bar 8.
Period II divides in the middle of Bars 20, 24, 28, and 32.
Period III is not capable of subdivision.
Period IV has two momentary divisions, (1) at Bar 62, and (2) at Bar 64.
Bars 1-6: Subject in Alto, followed by short Codetta [B minor].
Bars 6-12: Tonal Answer in Treble [F sharp minor].
Bars 12-15: Codetta, modulating from F sharp minor to B minor.
Bars 15-21: Subject in Bass [B minor].
Bars 21-26: Episode I, modulating from B minor to F sharp minor.
Bars 26-32: Answer in Alto, with Counter-subject (appearing for the first time) in Bass [F sharp minor].
Bars 32-35: Episode II, modulating from F sharp minor to D major.
Bars 35-41: Subject in Treble, with Counter-subject in Alto [D major].
Bars 41-44: Episode III, modulating from D major to A major.
Bars 44-50: Subject in Bass, with Counter-subject in Treble [A major].
Bars 50-54: Episode IV, modulating from A major to F sharp minor.
Bars 54-60: Answer in Alto, with Counter-subject in Treble [F sharp minor].
Bars 60-69: Episode V, modulating from F sharp minor to B minor.
Bars 69-72: Subject in Alto. Counter-subject absent.
Bars 70-76: Stretto I. Subject in Bass. Counter-subject absent [E minor].
Bars 76-81: Episode VI, modulating from E minor to B minor.
Bars 81-87: Subject in Treble. Counter subject absent [B minor].
Bars 87-100: Coda [B minor].
Bars 96-99: Subject in Alto. Counter-subject absent [B minor].
Bars 97-99: Stretto II. Subject in Bass [B minor].
Bars 99-100: Subject in Treble, ornamented by passing notes [B minor].
Exposition: Bars 1-21.
Coda: Bars 87-100.
- 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.
- Both the Subject and Counter-subject are of remarkable construction, the former for its “Octave drops” in Bar 3 and 4, and the latter for the descending sequence of its first two bars, and for its drops of the minor and major sevenths in semiquavers (sixteenth notes).
- The Counter-subject does note appear in the Exposition, its first appearance being at Bar 29.
- It is late in joining hands even when the Subject has begun, not joining till its third bar (see Bars 26-29). At Bar 86 its latter part is transferred from the Alto to the Bass.
- Stretto I is incomplete. Stretto II is complete as far as the three parts are concerned, though but very little of the subject is quoted.
- Six Episodes:
- Episode I (Bar 32) is in two parts. A free canon on figures which follow the first enunciation of the Subject in the Alto part is proposed by the Bass and imitated at a bar’s distance by the Treble.
- Episode II (Bar 32) is in two parts. A free canon on figures which follow the first enunciation of the Subject in the Alto part is proposed by the Bass and imitated at a bar’s distance by the Treble.
- Episode III (Bar 41) is formed from reminiscences of the Subject in the two upper parts, with detached figures in the Bass.
- Episode IV (Bar 50) has a running Bass formed from reminiscences of the Subject, with complementary upper parts.
- Episode V (Bar 60) is in free imitation and is formed on the figure seen in the short Codetta of the Alto of Bar 6.
- Episode VI (Bar 76) is much the same in construction as Episode V, the Alto having detached figures assigned to it.