The Well-Tempered Clavier, Book 1

(BWV 846-869)

The Well-Tempered Clavier 1 is a collection of educational pieces with exceptionally high artistic contents. From all the works written in the Baroque era, no other work has been so well-cherished, frequently performed and thoroughly studied than this work of Bach's. Hence many interesting episodes relating to this work can be found. Among the most interesting are Hans von Bülow's aphorism "Pianists' Old Testament" and R. Schumann's "Pianists' Daily Bread" — which, incidentally, can still be heard in music education today.

Though the Well-Tempered Clavier (hereafter WTC) was not published during Bach's lifetime, many manuscript copies were made by his pupils and copies spread steadily all over Europe with his fame. Influential musicians such as Mozart and Beethoven received manuscripts and as everyone knows, these composers in turn influenced the direction of the Western music. The WTC was finally published 51 years after the composer's death, which marked the culmination of the strenuous efforts made by his son and pupils.

Title and Historical Background
History of Conception and Revision Process
Historical Position
Structure, Forms and Styles
Some Issues on Performance


Bach's autograph fair copy (in the possession of the Staatsbibliothek zu Berlin Preußischer Kulturbesitz) bears the following title page:

The Well-Tempered Clavier,
Preludes and Fugues
through all the tones and semitones
both as regards the tertia major or Ut Re Mi
and as concerns the tertia minor or Re Mi Fa.
For the Use and Profit of the Musical Youth Desirous of Learning
as well as for the Pastime of those Already Skilled in this Study
drawn up and written by Johann Sebastian Bach.
p.t. Capellmeister to His Serene Highness
the Prince of Anhalt-Cöthen, etc.
and Director of
His Chamber Music.
Anno 1722."

Image of a title page

The inclusion of an abstruse word, 'well-tempered', suggests that in those days, well-tuned keyboard instruments on which the pieces written in all the 24 keys could be played were uncommon. From the second half of the 18th century to the middle of the 20th century, it was commonly thought that this word meant 'equal-temperament'. When we follow the trail of the word's historical significance, we ultimately arrive at the history of tuning methods advocated by A. Werckmeister. Related to this development was another historical change, namely, the establishment of the tonal system. Since the beginning of the Baroque era, a variety of church modes eventually became reduced to about two, and freer modulation became possible. As a result, an increased number of major and minor keys were available for common use. Thus it was not surprising that Bach considered launching such a project using all these theoretically possible keys. In this sense, this work can be seen to be epoch-making and evoking new ideas in the mind of the later generations.

However, J. M. Barbour questioned the traditional view. In 1947, he proposed that this work should be interpreted as 'Well-Tuned Piano'. Later, it became fashionable to regard 'well-tempered' as a kind of unequal temperament and scholars made various attempts to ascertain the temperament used by Bach. Under this type of tuning methods, every chord has a distinctive colour as a result of having pure or impure intervals determined by the chosen temperament. This argument was yet again overthrown by the comprehensive research by R. Rasch in 1985, who proposed that Bach's 'well-tempered' meant 'equal-tempered'. His view may seem ludicrous to many. Yet if we consider the accounts relating to Bach's own views on tuning as discussed by his son and pupils, together with the fact that Bach himself transposed his pieces widely and frequently, it is not too difficult to accept Rasch's view.

The 'clavier' means 'keyboard' - though no specific instruments under this name ever existed. Until the beginning of the 20th century, it was generally thought to mean 'clavichord'. Indeed there is evidence for it being referred to as 'clavichord' at the end of the 18th century. Recently, however, it has emerged that the word 'clavier' in Bach's time referred to 'keyboard instrument' in general. A closer study of his scores indicates that Bach did not directly follow this trend; he apparently distinguished the organ from the other smaller stringed keyboard instruments, which he collectively called 'clavier'. These clavier instruments can be roughly categorised as clavichord, fortepiano and harpsichord. Bach's classification of instruments was also a convenient way to refer to a particular character of sound and timbre, as well as the physical size of the instruments. Indeed such distinctions are important for a composer: it was an absolute requirement for him to consider the place where the piece was to be performed and the purpose of the composition, let alone the relationships between the performer and the listeners. These are also all relevant points when we discuss the style and character of music.

Another topic commonly debated is Bach's choice of an instrument for the WTC I. Some pieces are definitely suited to organ, such as fugues no. 4 and no. 20. But it must have been the 'clavier' instrument to which Bach had regular access at home, as we are informed by the recollection of H. N. Gerber (discussed below). When the WTC I was to be performed in its entirety on a single instrument, there would have been nothing better than to choose a harpsichord which is equipped with several stops. There were some arguments in the past with regard to the limited pitch range of C to c''' used in this collection. The traditional view that Bach intended the work to be performed on his clavichord with the keyboard compass of four octaves seems a little too confined. It is more logical to suppose that Bach considered the limitation to suit the needs of an unspecified number of prospective learners and performers. For him, a wider dissemination of the work must also have been an important consideration.


The year '1722' (inscribed in the title-page) was a crucial turning point in Bach's entire career. In that year, Prince Leopold, his employer, married a Princess who was known for her ignorance in music. Because of this situation at the court of Cöthen, he had never felt so awkward to remain in his position and so, by the end of that year, he had already made up his mind and sought a post in Leipzig. The WTC I was completed during this period. Bach was apparently deeply engaged in keyboard works of an educational nature; from this period date two similar (though smaller) collections, namely the Clavierbüchlein for Anna Magdalena Bach (Bach had married her at the end of the previous year) and the fair copy of Inventions and Sinfonias, which was completed in the following year.

Through recent studies of the surviving manuscript sources, the most notable of which are those by A. Dürr and R. Jones, it has emerged that the work was compiled over many years and that Bach seemed to have gathered some pieces which he had written previously, revising them repeatedly and improving them constantly for perfection. Examining the structural development of the work, it appears that the system of the WTC — namely a prelude-fugue pair, starting from C major and ascending on chromatic scale until reaching B minor while maintaining the alternation between the major and minor keys — was gradually formed. Furthermore, the manuscript sources that can be considered to have stemmed from an early autographic score (which is lost) attest numerous textual variants in the early shape of the text. The fact that these observations coincide with equivalent information contained in the other contemporary works by Bach gives much credibility to the integrity of such information, which in turn, becomes valuable chronological evidence. Further back along this line of the enquiries lies J. C. F. Fischer's idea (which is discussed below). Characteristics apparent in some of the fugue subjects used by Fischer are also evident in the WTC. This leaves little doubt that Fischer was the model of inspiration for Bach.

To some extent, it is possible to reconstruct the early part of the compiling and revision process of the WTC I in three stages (from α1 to α3). Firstly, in stage α1, twelve preludes from the first fifteen (nos. 9, 11 and 14 are excluded) are shorter than the final version. All the fugues are entitled 'fughetta' (meaning 'little fugue'), though the pieces themselves do not show signs of major revisions except nos. 15 and 22 (both of which are one bar shorter than their final version). Stages α2 and α3 are reflected in the Clavierbüchlein for Wilhelm Friedemann Bach, which was written in 1720 for his eldest son who then was nine years of age. In it we find 11 preludes in the form of an early version: stage α2 consists of pieces from C major to F major on an ascending diatonic scale (C, c, d, D, e, E, F); stage α3 consists of pieces filling the gap to form a fully chromatic scale (C#, c#, eb, f (though Eb is missing). Turning our attention to the musical maturity of the pieces, we find that α2 is a slight improvement on stage α1, whereas α3 is much closer to the final version. Thus we can confirm a definite chronological lapse between these stages. The manuscript copied during a period from the end of 1722 into 1723 by one of Bach's pupils (known to Bach scholars as Anon.5) also reflects this stage α3. Here we find all the 24 prelude-fugue pairs arranged on the chromatic scale. It, however, shows a trace of the diatonic scale arrangement seen in a2 in the form of the interchange between major and minor keys (i.e., d/D, e/E and a/A). This manuscript was later updated to the version of the autographic fair copy, but nonetheless the initial readings are still legible. More important is the fact that even at this stage, all the first fifteen preludes were already fully developed, transformed from short études to respectable pieces comparable in size and content to the accompanying fugues. In the light of both musical style and technical requirements for performers, we can establish the identity of α2 as a group, thus suggesting that these pieces were composed closely together. Yet, when we look at the overall history of the revisions, we notice an interesting fact: while the fugues were virtually untouched, the preludes were extended considerably in length. It may well be the case that the pair of preludes and fugues in this collection originated separately to some extent, especially since there is no fugue found in α2.

In completing the collection, one of the most challenging tasks for Bach must have been the composing of the pieces in those keys which he very rarely used, even in modulated passages. In fact there is no evidence that Bach had ever written pieces in the keys which have more than 4 flats or sharps in the key-signature, prior to the WTC I. It is fascinating to find, therefore, that some manuscript sources contain evidence of transposition being carried out from simpler keys: no. 8 (eb/d#, from e/d respectively), no. 18 (g#, from g), and no. 24 (b, from c). In addition, the notation of key-signatures contains some degree of chronological information: Bach often used modal key-signatures (with one sharp or flat fewer than our modern form) for his early versions.

Time-signatures are another notational element which determines the character of the pieces: they also went through gradual refinement in character, for some evidence can be identified in the time-signature of preludes no. 8 (from 3/4 to 3/2) and no. 13 (from 12/8 to 12/16).

Thus draft manuscript was completed by 1722, and there followed the autographic fair copy intended to be the final, definitive version. Although the manuscript exhibits frequent emendations as a result of his continual usage for over 20 years, Bach's beautiful calligraphy points to his sparkling confidence. It speaks to us of his great affection for this project and his aim of bringing it to a satisfactory conclusion. At the end of the volume is written "S.D.G" (Soli Deo Gloria), which is a customary signature by Bach to conclude a fair copy volume. Nothing is known about whether or not Bach considered having the work published at this stage. When his pupils needed to learn the pieces, Bach apparently lent them his earlier draft which was updated from time to time: it is likely that Bach did not lend his fair copy for at least another 20 years. Such untold history is hidden in the copies made by his pupils.

Bach's revision is in itself very fascinating. The study by W. Dehnhard in 1977 shows that Bach revised his fair copy manuscript in four stages (from A1 to A4). According to him, A1 refers to the initial state of reading when the manuscript was made, allowing for the earliest corrections, plus an intriguing revision to the last fugue. A2 includes extensive revisions in prelude no. 3 and fugue no. 6. This stage corresponds with the manuscript copy started by Anna Magdalena in 1733. In fact the inscription "1732" found at the end of the autographic fair copy may indicate the end of this phase of revision. A3 includes the extensive revision to fugue no. 1 and minor revisions to nos. 9 and 15. This stage can be dated around 1737 after Bach received the title of 'Composer to the Royal Court Capelle' at Dresden. A4 is the most extensive revision of all, affecting many movements. This can be dated around 1742 coinciding with the completion of the second volume of WTC. At that time Bach was working on a series of monumental keyboard pieces, and surely this latest revision of WTC I was a part of that year's activity.

The revisions on the preludes are, in general, restricted to subtle decoration of the texture in order to bring out more clearly the inherent character of the preludes; also we notice the insertion of newly-composed parts which help to achieve structural stability and formal integrity. The revisions on the fugues are rather different, in that some of the revised part-writings attest to an attempt to disobey the rules of textbook-style counterpoint. In fugue no. 1, the subject itself receives new rhythmic treatment as a result. Such instances reflect the idea that both fugue subject and contrapuntal logic have the capacity to process philosophical thought in music, which should be manifested even more clearly in performance.


Bach's explanation of "all the 24 keys" in the title page is wordy and somewhat bizarre. This must reflect the fact that Bach was unable to find a better phrase to explain the concept more neatly at the time of writing. Yet several similar attempts had already been made in the 20 years before him: in 1702 J. P. Treiber published Sonderbare Invention: eine Arie in einer einzigen Melodey aus allen Tonen und Accorden auch jederley Tacten zu componiren, and two years later, Der accurate Organist im General-Bass. Then in 1719, J. Mattheson published Exemplarische Organisten-Probe im Artikel vom General-Bass, which contained 48 examples in all the 24 keys. G. Kirchhoff, who was the same age as Bach — and presumably they knew each other — also wrote a similar work entitled L'ABC musical: Praeludia und Fugen aus allen Tönen. Yet the most influential of all was Ariadne Musica by J. C. F. Fischer published in 1702: it was reported by his son that Bach studied Fischer, whose work containing 20 preludes and fugues shows unmistakable identity with the WTC in the shape of fugue subject and the way the volume is organised. Thus there is little doubt that Bach used Fischer's Ariadne Musica as the model for his collection.

What, then, were Bach's objectives? Apart from the fact that he wanted to use all the keys, perhaps he intended to compile a collection of pieces covering diverse styles at the highest degree of artistic content and integrity as a whole. Here we can see a trichotomous image of Bach as distinguished composer, performer and educator.


Comparing the preludes and fugues composed specifically for organ with those in the WTC I, we may notice that in the WTC I they are apparently shorter and more modest in their expressive means. To certain extent this may apply to all the clavier pieces; we would expect the relationship between performer and listeners in the domestic environment to be more intimate, conducive to sharing the musical experience.

Doubtless such pieces full of artistic content are the best textbook for those learning composition or performance. Bach first began writing large-scale composition of this nature - namely Orgelbüchlein from Weimar period - some 9 years before the WTC I was completed. In his own system of clavier teaching, the WTC was placed at the final stage. It was reported that H. N. Gerber, who studied under Bach between 1724 and 1726, told his son of his experience with Bach. That story was published in 1790 by Gerber's son under the title of Historisch-Biographisches Lexicon der Tonkünstler:

"At the first lesson he set his Inventions before him. When he had studied these through to Bach's satisfaction, there followed a series of suites, then the WTC. This latter work Bach played altogether three times through for him with his unmatchable art, and my father counted these among his happiest hours, when Bach, under the pretext of not feeling in the mood to teach, sat himself at one of his fine instruments and thus turned these hours into minutes."

Here we can witness his philosophy in education: pieces put in front of the student should be of sufficient variety, richness of style and form that the student is motivated strongly to learn.


As the churches in Bach's time were built in the symmetric form, the concept of symmetry, which originates in the cross of Christ, dominated the structure of the piece, penetrating deep into the constituting elements of music and the musical form itself. If we divide the WTC I into two halves, we then notice that the concluding movement from each section is built around an identical compositional concept: in section 1 (no. 12), all the twelve semitones are covered by the subject and the answer, while in section 2 (no. 24), they are contained in the single subject entry. This can be thought of as the symbolic representation of the concept — 'all the keys'. If we extend our search into the details by dividing the sections further, we find sub-divisions in threes, marked by the large fugues in minor keys, namely nos. 4, 8, 20 and 24 (no. 16 is not that substantial, however).

From a different angle, we can also find a concept of symmetry in the number of voices used in the fugues: in each section there is one 5-part fugue written in stile antico; In the first section, there are seven 3-part fugues (plus three 4-part and one 2-part), while there are seven 4-part (plus four 3-part) in the second half. ('Seven' and 'twelve' [3 x 4 or 4 x 3], often quoted as 'holy numbers', seem to be stressed here by Bach.)

There is some evidence in the WTC I suggesting that this was intended to be a mikrokosmos. The fact that the WTC I begins with the simplest of preludes and ends with a fugue of an extensive, most complicated nature cannot be a mere coincidence. The work also embraces pieces in diverse forms and styles, encompassing all the possible varieties of the day, including quasi-vocal fugue in stile antico, dance movement, virtuoso impromptu, and others.

Restricting our discussion to preludes, we can classify them in terms of their form, as follows: homophonic pieces — nos. 1, 2, 5, 6, 10, 15, 21; polyphonic 2-part Inventions — nos. 3, 11, 13, 14, 20; 3-part Sinfonias — nos. 9, 18, 19, 23; various kinds of arioso — nos. 4, 8, 16, 22; a concerto — no. 17; a trio sonata — no. 24; a sonorous, 4-part contrapuntal piece — no. 12; and a toccata-like introduction with a double fugue — no. 7.

Fugues are often classified according to the number of voices and the contrapuntal techniques used. It is also possible to some extent to approach from so-called 'Charakterthema' in H. Besseler's term, or from a stylistic classification, as viewed from a chronological perspective.

The musical form of the prelude-fugue pair traditionally meant what the term implies; preludes were originally short, mirroring the early development process of WTC I already discussed. The original function of preludes was to establish the tonic key on which the fugue exposed its rich musical discourse. In the WTC I however, the preludes began to acquire the character of an étude as well as that of an artistic piece in its own right. This tendency is even more clearly seen in the WTC II.


In search of the 'authentic' performance, selecting the original instrument is just the starting point. Should we aim for historical accuracy according to Bach's intention as closely as possible? Or do we approach a performance from our modern aesthetic milieu, in order to reconstruct the history of the period? In either way, it is necessary to understand the elements of musical organisms, such as ornamentation and the correct interpretation of rhythm and tempo when we realise the fact that music has never been intended to be interpreted as actual sound itself but the expressive character of musical ideas.

It is well-known that Bach wrote in many more ornaments than the standard practice of his time. In his day, it was the performers' task to add ornaments and embellishments as a part of expressing the music according to its melodic shape, its harmonic progression and associated texture. Thus knowledge about many diverse styles of music was the essential requirement to be a good performer. The examples of Bach's teaching on this aspect can be seen in some of the surviving manuscripts, to which Bach apparently added some ornaments during lessons with his pupils. It is worth adding that the ornamentation is also determined by several other external factors, such as the tone characteristics of the instrument selected and the acoustics of the room used.

Bach's clavier pieces do not often bear tempo marks. This is partly due to the domestic and educational nature of these compositions. When learning pieces from the WTC, his pupils were expected to study not only how to play the correct notes, but also how to interpret individual pieces correctly. All this is actually contained in the form of musical notation. The source of information resides in the use of a variety of time-signatures, the way the main motifs are shaped, and the way the texture is formulated. The tempo signs written in the WTC I are all exceptional cases, which are intended to clarify the composer's intention. Here Bach used five kinds, namely Adagio, Largo, Andante, Allegro and Presto: they appear in preludes no. 2 (Presto, Adagio, Allegro), no. 10 (Presto), no. 24 (Andante) and its accompanying fugue (Largo). It is important to note that they do not indicate the absolute tempo, as we would understand it today. In Bach's time the tempo indication meant its emotional character, which in turn suggested the speed to which it belonged.

Thus the deeper we study Bach's music from a historical perspective, the better we understand the historical meaning hidden deep in individual notes. There we may discover a bygone world — the eternal dimension in which to search for an approximation of historical truth.

(c) Yo Tomita, 1996 [updates are entered in the form of pop-up comments over the text in red/underline]

This essay is inspired by the performance of the work on the harpsichord by Masaaki Suzuki, 1996, and is used for his CD (BIS-CD-813/814) released in January 1997 from BIS.