WTC II/5 in D major – Prelude 

    from Siglind Bruhn
J.S. Bach's Well-Tempered Clavier
In-depth Analysis and Interpretation

II/5.1.1 The prelude-type

The first question to arise when tackling this prelude is that of texture. On the surface, the piece appears as a polyphonic composition, yet there are several passages which, like the opening, are clearly homophonic in setting. Further observations do not immediately clear these doubts. On the one hand, we find consistent writing in three parts which is abandoned only for rare instances of voice splitting (see in bars 18-20, 28/29, 40 and 56); moreover, most compositional techniques expected in polyphonic works: imitation and instances of contrapuntal setting, sequencing and inversion of motives as well as motivic development are employed. On the other hand, closer inspection reveals that many of those bars which at first glance seem to contain independent voices actually represent homophony in disguise: only one voice is melodically active while the others either describe ornamented parallels or rhythmically embellished accompaniment-figures.

This dichotomy between polyphonic and homophonic elements continues in the choice of the thematic material and in the structural design. On the one hand, the ubiquitous presence of a single motive recalls the design of inventions. On the other hand, the distinctive coloring of segments of this motive and its use in separate sections of the piece, together with the ternary layout of the work and its particular harmonic development, suggest classical form scheme.


II/5.1.2 The overall design of the prelude

While the main motive of the prelude (see bars 1-3d, 3-5d) concludes with the essential steps of a cadence, the fact that regular participation of all voices is suspended during the initial four bars discourages us to interpret this harmonic closure as relevant for the overall structural layout. The first complete cadential formula occurs thus in bars 12/13, after a modulation towards the dominant which begins in bar 5. The dominant key is then confirmed in another cadence (bar 16).

The following section appears similarly built. The four opening bars remain in A major but fail to convince as a structural section of their own. They are followed by an extended process of modulation which eventually closes with a cadential formula in B minor, the relative key of D major (see bars 32/33). A shorter section follows which brings forth the return to the home key (bars 40/41).

From bar 41 onwards a recapitulation follows which, notwithstanding some small modifications and harmonically caused adjustments, is a true review of the first sixteen bars of the prelude. The relevant harmonic movements encompass a modulation to the subdominant within the initial four bars (concluded in bars 44/45), the return to the tonic (bars 52/53) and the confirmation of the home key within the final four bars. The following schema sums this up:

bars 1-5d

4 bars opening

D major – D major

bars 5-13d

8 bars modulation (1 fifth up)

D major – A major

bars 13-16

4 bars

confirmation A major – A major

bars 17-21d

4 bars opening

A major – A major

bars 21-33d

12 bars modulation

A major – B minor

bars 33-41d

8 bars return to the tonic

B minor – D major

bars 41-45d

4 bars modulation (1 fifth down)

D major – G major

bars 45-53d

8 bars modulation (1 fifth up)

G major – D major

bars 53-56

4 bars confirmation

D major – D major



II/5.1.3 Practical considerations for performers

The character of this prelude is rather lively. This is indicated, on the one hand, in the broken chords and ornamental sixteenth-notes and, on the other hand, in the way Bach expressed his idea of meter. The double time signature is in fact quite revealing: while the twelve-eight reflects typical Baroque reluctance to accept triplets as basic note values, the alla breve not only hints at the occasional suspension of the compound metric pattern in favor of a simpler order, but also determines what the main beat is to be: the half-bar pulse.

While such a twofold time signature may appear confusing at first glance, doubt about the actual value of the eighth-notes does not arise: it is all too obvious that they take up a third of a quarter-note in all patterns like that of bar 1, but half of a quarter-note in all patterns like that in the second half of bar 2. It is, however, important to notice that Bach seems to conceive all notes outside the "groups of three" in the alla breve pulse. Thus wherever he uses accompanying rhythms in gigue-style, he writes these in dotted rhythm (see e.g. bars 5-7, 12, 16 etc., and bars 23-26). These dotted-note groups have the rhythmic value which matches the triplets, i.e. they stand for a quarter-note-plus-eighth-note combination. (The composer may have avoided writing this way because he is using the quarter-note as a larger unit – half of the half-note beat – elsewhere and would thus have created more confusion with two kinds of quarter-notes.)

The tempo of this prelude has to combine two traits: swiftness (in the sixteenth-notes) and stateliness (in the quarter-notes and non-triplet eighth-notes). The triplet eighth-notes act as a link between the two sides; a good way to approach them is to make it a point not to think in groups of three but in groups of six, in accordance with the alla breve request.

Ornaments occur in various forms. The cadential mordents in bars 12 and 32 commence on the main note in an interpretation which stresses melodic steps, but may begin on the upper note – despite the note repetition thus created – in case the approach to the piece focuses on the virtuoso element. More melodically defined mordents like the one in bar 23, however, must begin on the main note.

The inverted mordents in bars 13 and 33 obey the key of the bar and thus touch down on the leading-notes G# and A# respectively. The inverted mordents in bars 13/14/15 should be transferred to the corresponding bars 53/54/55.

The long trills need to be carefully timed as they appear in combination with triplet-eighth-notes (bar 19), duplet-eighth-notes (bar 20) and triplet-based sixteenth-notes (bar 40). The tempo of the shakes must obviously be the same in all cases, i.e. triplet-based thirty-second-notes. This poses a different number of ornamental notes against each note of the accompanying voice: 4:1 in bar 19, 6:1 in bar 20 and 2:1 in bar 40. The two former ornaments come as unresolved trills which end without suffix in a tie. The first one (bar 19) begins on the main note which is therefore prolonged to a sixteenth-note, while the second one begins on the upper note and starts shaking right away. Both stop short on the final thirty-second-note before the bar line. The ornament in bar 40, by contrast, is resolved on the following strong beat and thus ends regularly (beginning on the upper neighboring note, shaking in thirty-second-notes, ending with a suffix).

To further enhance the stately character of the prelude it is possible (though by no means necessary) to add ornaments in certain typically-used patterns, although they are not specifically indicated here. Notes which could be thus enhanced are: the first dotted note in a group (see e.g. L: bars 5 and 6, second quarter-note, etc.) and the final top-voice note in otherwise unornamented cadential patterns (see e.g. U: bars 16m, 56m). Such additional ornamentation emphasizes the ceremonious aspect of the piece; an interpretation which aims to concentrate on the polyphonic features would therefore not make use of them.


II/5.1.4 What is happening in this prelude

The prelude begins in almost orchestral colors. The opening downbeat-octave – a feature not usually associated with Bach's musical language – is followed by a figure which, in its combination of run + zigzagging broken chord, reminds one of a fanfare. The effect is completed in the one-bar cadential pattern which, in straightforward homophony and with strong emphasis on metric order, evokes an orchestral tutti picking up after a solo gesture. "Fanfare" and "tutti cadence" are then repeated (see bars 3-5d: U/M inverted, L one octave lower).

From bar 5 onwards, the character is different. The absence of any homophonic doubling and the appearance of a kind of dialogue between the upper and middle voices seems to suggest (to remain in the picture) a change of instrumentation from larger ensemble to chamber-music setting. In this new color, the "fanfare" is used in a much shorter and therefore less clamorous version, alternating in inversion (M) and original (U). The dynamic outburst traditionally inherent in fanfares appears softened to a gentle little crescendo which becomes even more subdued in the lower sequence (bar 6). When the figure recurs in its original length (bars 7-8d: L, 10-11d: M, 11-12: U), the aggressive character is considerably softened first by the middle-voice position, then by the inverted shape.

Bars 5-7 and 10/11 are accompanied by a four-note rhythmic figure which retains some of the stateliness of the opening bars (see L: bars 5, 6, U: bar 7; L: bars 10, 11). Yet even these "drum-beats" come interspersed with softening runs (see L: bars 5/6, 6/7, 10/11). Inside this bracket built by the "drum-beats", the two components which originally made up the "fanfare", run and zigzagging broken chord, are split between upper and lower voice in bar 8, and only runs are left over in bar 9. A cadential formula closes the development in bars 12/13.

The four bars that remain before the repeat sign present a three-bar descending sequence (compare the second to ninth eighth-note in bar 13 with the same segment in bars 14 and 15). The material consists of varied fragments of the "fanfare" (descending runs and a three-note broken chord) as well as the "drum-beat" – here with an ornament replacing the dotted-note group. The fourth bar adds a renewed cadential close in the dominant.

If we stop at this point and estimate what we have found out about both material and form in this prelude, two terms spring to mind.


All components of the thematic material, even when expressing different "colors", are derived from the initial two bars of the piece. The "fanfare" may appear split into fragments of various length, the homophonic cadential formula may assume different shapes, and the opening assertive octave beat may turn into different "drum-beat" patterns; yet all can be traced back to a single two-bar cell.


The overall design of the prelude reveals ternary form, with some specific attributes: The initial portion is not only repeated but recurs in exactly corresponding design and material. The significant difference lies not in the inversion of voices (compare U/M: bars 1-9 with M/U: bars 41-49) or the few melodic variations (compare bars 13-16 with bars 53-56), but in the harmonic development. An exposition which modulates to the dominant and is then repeated, followed by a middle section and then by a recapitulation which begins and closes on the tonic certainly suggests sonata form!

We are thus dealing here with a prelude in sonata form based on a single thematic cell – in other words: a monothematic sonata movement.

The middle section fits well into the notion of "development section". Bars 17-20 are based on the "main motive", i.e. the combination of octave-beat, "fanfare" and cadential close. For the first time in the prelude, the entire two-bar unit appears in inversion and at the same time contrasted with a counterpoint (U: bars 18-20). In bars 21-33d, Bach develops the "chamber-music" version of the thematic components as it appeared in bars 5-14d (in a way: the "secondary theme" within the sonata form). Familiar passages with only little modification (see e.g. U/M: bars 21-23d and L: bars 23-25d) are set against new material (see L: bars 21-23d and U/M bars 223-25d). The combination is then further developed (bars 25/26), gives way momentarily to disguised parallels and virtuoso figures (bars 27-27) and ends by returning to familiar grounds (compare: bar 30 with bar 11, bar 31 with bar 10, bar 32 with bar 12). The third portion within the development section begins in bar 33 in the same way as did, in bar 13, the third portion within the exposition. Bars 34-40, however, display new material which in simple pitch lines (bars 34/35: descending sequences; bars 36/37: ascending sequences; bars 38/39: descending sequences) prepares the transition to the recapitulation.



WTC II/5 in D major – Fugue


II/5.2.1 The subject

Commencing on the second eighth-note of an alla breve bar, the subject of this fugue concludes after the time of three half-notes, on the middle beat of bar 2. Its line falls from the octave to the third of the D major scale. (The harmonic resolution, the logic of metrical organization and also Bach's further use of the subject prove that the D on the last quarter-note of bar 2 does not belong to the subject!)

In terms of phrase structure, the subject consists of a simple, indivisible unit. This is particularly noteworthy in this piece as the second half of the subject, used as a motive, permeates the entire composition so densely and frequently that one might be tempted to regard it as separable from the initial bar.

The rhythmic pattern in the subject comprises eighth-notes, quarter-notes and a syncopated note of three-eighth-note duration. (The same note values are maintained throughout the fugue, increased only by a negligible number of sixteenth-notes.) The pitch pattern in the subject consists of the initial note repetition followed by a broken chord, two consecutive larger jumps (a perfect fifth and a perfect fourth) and only two steps at the very end.

Harmonically, the subject is designed as a simple cadence I-ii-V-I. The repeated D represents I, followed by ii in the second half of bar 1; with the beginning of the new bar, i.e. during the course of the tied syncopation, the harmony changes to a V9 chord and resolves to I on the middle beat of this bar. (This harmonic layout demonstrates clearly the indivisibility of the subject.)

(ex. 51)

The dynamic development expresses both the harmonic design and the particular metric/rhythmic organization since the two coincide with regard to their tension-enhancing features. The tied note B is the obvious choice for a climax as it is not only a syncopation (and as such the most striking feature in this short unit) but also represents the shift from one harmonic step to another, a fact which confers additional tension to this note.



II/5.2.2 The statements of the subject

This fugue encompasses twenty-four subject statements.



bars 1/2



bars 27-29



bars 2-4



bars 27-29



bars 5/6



bars 28/29



bars 6/7



bars 33/34



bars 10/11



bars 33/34



bars 11-13



bars 33-35



bars 14/15



bars 40/41



bars 14-16



bars 43/44



bars 21/22



bars 44-46



bars 22/23



bars 44-46



bars 22-24



bars 45/46



bars 25/26



bars 45/46


(ex. 52)


Of these numerous entries, only one is varied: the alto statement in bars 28/29 substitutes the syncopation with a rest and transposes the four final notes a fourth up. Modifications of the beginning or the end do not occur. There are no interval adjustments in the answer, and the subject is never inverted. Strettos, however, are frequent and involve from two entries (already in the first section; see bars 5-7) to all four parts (see bars 44-46).



II/5.2.3 The counter-subjects

Bach does not develop any independent thematic entity as a counterpoint to the subject. The tendency he already displayed in the prelude is continued in the secondary material of the fugue which derives entirely from the subject itself, thus giving this piece a singularly dense atmosphere.

The four final notes of the subject (which, for simpler reference, will be called Ms) appear both as a counterpart to the subject and as an episode motive. When accompanying the subject it can appear in three positions:


as a rhythmic complement, commencing after the fourth subject note
(see bars 3, 5, 6, 10, 21, 25, 40)


as a rhythmic parallel to the beginning eighth-note motion
(see bars 5, 11, 14, 21, 25, 33)


as a stretto imitation to the subject's ending
(see bars 7, 29, 34, 41)


(ex. 53)



II/5.2.4 The episodes

The D major fugue includes ten subject-free passages.



bars 4 - 5d


bars 26m - 27m


bars 7m - 10d


bars 29m - 33d


bars 13 - 14d


bars 35 - 40d


bars 16 - 21d


bars 41m - 43


bars 24 - 25d


bars 47 - 50

One of the episodes is subdivided: in E4 we must distinguish a main section which closes with a cadential formula in the middle of bar 20, and a half-bar appendix which prepares the next subject statement.

In the absence of independent episode material, none of these subject-free passages presents a contrast to the subject-determined portions. On the contrary, all episodes sound almost as extensions to the preceding entry. This effect is achieved by Ms, the four-note group from the end of the subject. Among the episodes we can distinguish four groups:


those which begin as a partial sequence, i.e. with Ms in the voice that just presented the subject --

see E1 bars 4/5:

subject ending in A, Ms sequence in A, imitated in T;

see E3 bars 13/14:

subject ending in S, two Ms sequences in S;

see E5 bars 24/25:

subject ending in A, Ms sequence in A, imitated in T;


those which begin as a stretto imitation, often involving many entries of Ms -

see E2 bars 7-9:

subject ending in B imitated in uninterrupted stretto
with A/T/S/B/A/T; non-stretto imitation in B;

see E7 bars 29-32:

subject ending in A imitated in uninterrupted stretto
with T/S/A/B/S/T/A; second stretto with A+T/B;
non-stretto imitation in B;

see E9 bars 41-43:

subject ending in T imitated in stretto with A/Svar,
non-stretto imitations in T+B and in S;


those which follow a subject stretto in (non-overlapping) Ms strettos:

see E4 bars 16-20:

ending of subject stretto (A/S) imitated by
stretto 1 with A/S/A; stretto 2 with T/S/T;
stretto 3 with B/S/B/A/T;
non-stretto imitation in B;

see E8 bars 35-39:

ending of subject stretto (T/A/S) imitated by
first stretto with T/A/S;
stretto 2 with T/A/S/T/B/A/B/S/A+B/S/A;
non-stretto imitations in A and in S

see E10 bars 46-50:

ending of subject stretto (S/A/T/B) imitated by
stretto 1 with T/S/B/A; stretto 2 with T/B/A;
stretto 3 with T/A/S;
non-stretto imitation in T;


those which only serve to either prepare or close a subject entry:

see E4a bars 20m-21d:

single statement of Ms which serves, together with the two bass notes, to modulate from A major to B major;

see E6 bars 26m-27m

cadential formula in F# minor; no quotation of Ms.

The three episodes of type a) are identical in length and analogous in structure; they all serve as bridges between consecutive statements within a section. Their dynamic tendency is slightly rising.

The three episodes in group b) are longer. The striking density of their strettos is counteracted by descending peak-note lines (see E2: A-C#, E7: E-G, E9: D-F#). While the first of these lines features a closing-formula (see bars 9/10) and does in fact conclude a section, the conclusion is obviously intended to appear as transitory. (This is supported by the resolution chord on the downbeat of bar 10 which comes with a sudden drop in the texture: see the unexpected rest in the tenor.) The other two episodes of this group clearly have a linking function. The dynamic tendency of all three episodes is that of a very gradual lessening of tension.

The three episodes in group c) are all long and complex. Each of them concludes a section. In the case of E4 this is supported by the closing-formula (see S and B in bar 20); E10 at the end of the fugue does not raise any questions anyway. E8 does not contain any obvious closing features, but it very distinctly marks the return to the tonic (see particularly the two-octave descending scale in the bass of bars 38-40). Structured in themselves, these three episodes are also the most self-contained in their dynamic shape: E4 describes a curve, beginning with a buildup (see the special treatment of texture in bars 16-18) and ends with a definite relaxation; E8, despite its descending D major scale at the end, strikes the listener with steady ascents (see the chromatic ascent in the bass of bars 35/36, followed by ascending sequences, and the rising peak-notes in the soprano). The conclusion of this section is thus prepared as a triumph. E10 by contrast features exclusively descending lines and thus completes the piece on a soft note.


II/5.2.5 Character, tempo, articulation, ornament realization

The pitch pattern with its note repetition, broken chord and consecutive fifth and fourth interval clearly indicates a rather lively character, as does the rhythm pattern which, as was observed earlier, is basically simple throughout the fugue. The alla breve time signature supports this concept. The tempo, however, finds its upper limit in the desired clarity of the material: the density of the Ms strettos can be neither properly expressed nor fully perceived if the pace is too fast. The two beats in each alla breve bar can therefore best be imagined as generously swinging.

In view of the existing contrast in prevailing note values, the relative tempo of the prelude to the fugue may be chosen in simple proportion:

half a bar

corresponds with

half a bar

in the prelude

in the fugue

(Approximate metronome settings:
92 for the dotted quarter-notes in the prelude, 46 for the half-notes in the fugue)


The articulation includes non legato, quasi legato and legato.


Within the non legato we should distinguish between a more definite cut after the quarter-note (fourth subject note) and the much smoother interruption after the syncopation – smooth enough to guarantee that the syncopation can truly be heard as "swallowing up the strong beat".


The quasi legato too may sound denser in the ending of the subject (Ms) than in the note repetitions.


True legato applies to the few sixteenth-notes but also, more importantly, to the closing-formulas (see U: bars 20, 27, 44; M: bar 50). The score does not contain any ornament.


II/5.2.6 The design of the fugue

The layout of the piece has already been all but revealed in the context of the episodes. The fugue consists of five sections.



Section I comprises the initial subject statements (one in each of the four voices) together with the linking E1 and the concluding E2. The section closes in the dominant key (A major) on the downbeat of bar 10.


Section II presents two single entries of the subject followed after the bridging E3 by a stretto made up by the same voices; E4 concludes this section, once more in the dominant key of A major, in the middle of bar 20. As was already mentioned above, the cadential resolution in bar 10 appears unexpectedly weakened by a rest in the tenor, and thus creates an affiliation with the forthcoming section. The union of these two sections is further fortified harmonically: no new modulation takes place. Instead, the weakened A major cadence of bar 10 is taken up and led to a full-voiced close at the end of the second section.


Section III consists of the half-bar modulation in E4a, four entries (one in each voice) which partly overlap, the linking episode E5 and the cadential close in E6. From its initial modulation until the closing-formula, this section relates harmonically to B minor / B major and F# minor / F# major.


Section IV encompasses two tightly interwoven three-part strettos and two longer episodes with multiple strettos of Ms. It commences harmonically in the dominant key A major (stretto in the octave, see bars 27-29), progresses through the subdominant key G major (see the end of E7: bar 33d; also the end of the second stretto: bar 35d) and ends with a return to the tonic (see the downbeat of bar 40).


Section V begins with two single subject statements linked by E9. It is then crowned by the triumphant quadruple stretto, after which its tension subsides gradually throughout the descending lines of the final episode E10.

For a sketch showing the design of the fugue in D major, see ex. 54.



II/5.2.7 The overall dynamic outline of the fugue

The development of tension inside each section as well as in the entire fugue is determined by the occurrence of strettos and by the tendencies expressed in the episodes. Thus the first section describes a gentle curve: the tension rises through the four subject statements but declines in E2.

The second section brings forth a more powerful dynamic increase. Commencing in full four-part texture, it picks up the tension from the raised level of the previous development. The linking episode contains ascending sequences of Ms and thus aids the rising motion. The growth is furthered by the advent of the first stretto, and is doubled shortly in the first portion of the ensuing episode. Only then does the tension abate. The first and second section together thus build a pair not only on the harmonic level but also with regard to the development of tension.

The beginning of the third section marks a new beginning in terms of tension, enhanced by the change of harmony and the thinning of texture. Although the close position of the three opening entries. (These three entries feature halfway between a two-part and a three-part stretto: while three voices are involved in the overlapping, the first and the last do not actually share a beat.) propels the tension upwards again, the overall mood is more subdued than in the previous section. The single statement which follows and the simplicity of the closing episode underpin the lessening of drive in what is in fact the shortest section of this fugue.

The fourth and fifth sections together form another large pair, structurally comparable to that built by sections I + II:


Just as the A major cadence in bar 20 completed the somewhat transitory earlier A major cadence in bar 10, so does the D major cadence of the final bar here complete the return to the tonic which at the end of section IV had come without the support of any cadential formula.


Just as the four single entries of section I were surpassed not by the two single entries at the beginning of section II but by its stretto, so the two three-part strettos in section IV are outdone not by the two single entries at the beginning of section V but by its four-part stretto. The consistent decline of the pitch line in the final episode is understandable after such a powerful buildup.

Summing up the dynamic developments which shape the entire composition, we can thus state that two large-scale increases surround a softer section. While structurally corresponding, the second increase is at the same time also the continuation of the first.