sleep softly my old love
my beauty in the dark
night is a dream we have
as you know as you know
night is a dream you know
an old love in the dark
around you as you go
without end as you know
in the night where you go
sleep softly my old love
without end in the dark
in the love that you know
-- W.S. Merwin
The fugue is a temple set on the highest peak in the West. Covered in cloud and mist, reached only by winding path, it nonetheless overlooks the entire geography of musical history from the lost world of cloistered church modes to the cacophonic-anarchistic din of our times. It is filled with the arcane science of the combination of tones, catechisms of harmony both innovative and obsolete, and rituals of procedure both strict and free.
If the reader finds that description too fanciful to be helpful, perhaps the great composer and theorist Jean-Phillipe Rameau can offer a more grounded description: “Fugue is an adornment of music governed by no other principles than those of good taste.”
The vagueness of these descriptions is a reflection of the fugue’s place in history. While Bach’s Well-Tempered Clavier, in its utter completeness, is the marker of our modern conception, the term fugue had been in practice for over 400 years previous, and often used for music of widely divergent purpose.
In Alfred Mann’s detailed history of the fugue, he writes, “The term fugue holds a particular fascination for the student of music. It suggests the essence of polyphony, the most intricate expression of the complex language of Western music.” Although ordered polyphony has fallen out of favor at various points in time, it has always been viewed as a summit – either derided as a scientific one, or celebrated as an artistic one, as in Rameau’s “adornment.”
Confusion reigns over the historical application of the word. It derived from the Latin fuga, meaning to chase; it implies that one voice is “chased” after by another in imitation.
Later, this concept of one voice following or chasing another would link the aesthetic of the fugue to the art of rhetoric; fugues were ideas laid out in arguments, with all the structural elements of a speech and debate. Whatever the philosophical preference, fugue was always attached to music that involved imitative polyphony, rather than homophonic music or free polyphony. It sometimes was given to a strict canon, where the voices imitate each other exactly with no derivation; sometimes to polyphony bound overall to a fixed cantus firmus ; and sometimes involved a “theme” which could be heard throughout, or not.
Musically speaking the word fugue has been used to describe a texture (imitative polyphony), a procedure (rules for organizing separate imitative voices), or a form (the use of imitative polyphony to create an overall arced structure). To make a grammatical analogy, fugue could be a subject (the nature of the music itself), verb (how to compose, as in William Billings’ Fuguing Tunes, or object (the form of an individual piece as a whole).
Over time these categories began to sort themselves out in such a way that the fugue became inextricable from a major development in musical history, the movement from church modes to diatonic harmony. By the 17th century, composers had pretty much reached a consensus that a fugue required first a “point of imitation,” what we would today call a theme, followed by its answer at a fixed harmonic point.
The concept of a point of imitation, which seems for us to be an obvious idea, was the triumph of many centuries of experimentation that was often based in church tradition and Gregorian chant. While formulating that concept, composers throughout history referred to it in an array of terms: point, punto, plain song, air, ditty, thema, subject, invención, and so on. Rather than several freely-composed ideas in imitation, composers settled on one for each fugue that would be present throughout the whole piece.
The answer, being at a fixed harmonic distance from the theme, served to solidify the diatonic harmony that we recognize today, and move music away from its reliance on church modes. Coming after the theme at an interval of a fourth or fifth, the answer held powerful potential for modulation and return, the basic dramatic principle of diatonic music. The combination of ordered essence of polyphony and dramatic structure of harmony are the cornerstones of Bach’s achievement in the Well-Tempered Clavier, in my opinion.
But the world of diatonic harmony was not to be fully opened until tools could keep pace with thought. Now that that world was revealing itself, musicians strove to explore every island. The time before Bach was a charged, experimental age not unlike the age we are in now. Musicians needed instruments to advance technically, and thus arose the concept of a “well-tempered” keyboard instrument.
A well-tempered instrument is one that allows every key to be played in tune. Prior to the late 17th century, musicians used purity of fifths as the basis for tuning. This purity prevented variety. Tuning by fifths leads to enharmonic discrepancy (known as the Pythagorean comma) – A-flat and G# today sound the same, though in theory they are different pitches. In the ancient tunings, you could have one or the other, but not both. The same went for any enharmonic relationship: you could tune a keyboard to have an F#, or a G-flat, but not both. Well-tempered violated the pure proportions of all intervals except the octave, to balance the enharmonic discrepancy and allow every tonality to issue from one tuning. What was lost in purity was gained in possibility.
Bach seized on this possibility in The Well-Tempered Clavier. He was not the first to write a set of pieces in every key, but his achievement was the most complete and profound. Its influence on other composers lasted at least 200 years, and the sheer scope of his project still provokes awe today.
Simply put, The Well-Tempered Clavier is a collection of preludes and fugues written in every key. There are twelve notes in the chromatic scale, each one having a major and minor mode, thus 24 keys. There are two books because Bach amazingly did this twice, writing two preludes and fugues for each key, thus the ’48.’ The first book was completed in Cöthen in 1722; some hypothesized that he wrote several preludes and fugues for this book as a diversion while in jail. The second book was completed in 1742 in Leipzig. It recast some older music in combination with new pieces, especially preludes, that explored more modern styles. The second book is much longer in the whole than the first, and has more complex music, also especially in the preludes. The first book is more familiar because it is often played as a cycle in one concert, while the second book is full of longer, more dramatic preludes and fugues that seem to work today more as individual concert pieces.
The project as a whole displays Bach’s power as an encyclopaedist. Not only does he write a prelude and fugue in every key (twice), but he also included every meter in use at the time, all combinations of duple, triple, simple and compound. The preludes represent a wide swatch of historical genres: arpeggiated improvisations; 2-part inventions and 3-part sinfonias; ariosos; concertatos; trio sonatas; and toccata-fugue style combinations as the Northern German composers of old. Also he strove to make the fullest use of every fugal technique (here fugue as procedure, or verb) and their combinations: stretto, inversion, augmentation and diminution, double and triple fuguing.
In these fugal techniques is revealed both Bach’s art and science. He devised his themes purposefully towards the use of the various techniques – accounting for the science – but always placed them in service of a larger harmonic scheme employed to dramatic effect – accounting for the art. A few examples can reveal some of his purposes.
Bach used stretto, where the answer to the theme comes before the theme is fully stated, for varied effects; in the C major Fugue, Book I, a four-part stretto seems to contradict the humble nobility of the theme, leading to disagreement and modulation to the minor:
Whereas the four-part stretto of D major, Book II, is a fulfilled, consonant climax of the theme, leading to a peaceful coda:
The theme of B major, Book I,
when inverted (the intervals are reversed), is full of sweetness and joy – it never sounds in the minor mode or modulates to a minor key –
While the theme of a minor, Book I,
when inverted becomes a satirical parody:
The humorous C# major, Book II, theme,
becomes more serious as its augmentation (the note values are doubled) leads to the final pedal point and reflective coda:
Curiously, the a minor, Book II, contains both an original form and diminution (the note values are halved) in the theme itself:
A personal favorite excerpt of mine comes from c minor, Book II, where Bach puts together in three-part stretto the original, augmentation and inversion of the theme:
Bach’s fugues in The Well-Tempered Clavier are above all true to Rameau’s description – they are adornments of music. No two follow the same form, and the only “rule” observed is that a theme sounds by itself at the beginning, and then is answered. The number of voices varies from two to five, sometimes accumulating more at the end. This theme is the music to be adorned, the idea, the invention that creates the foundation of each fugue and makes each one a self-contained world.
A generous reader may now think my original definition more appropriate. I would hardly be the first to attach grandiose imagery to The Well-Tempered Clavier; the 19th century conductor Hans von Bülow called it “the Old Testament” of piano music, while Schumann, hinting at the Lord’s Prayer, described it as “daily bread.”
Bach signed many of his compositions at the end, S.D.G, or Soli Deo Gloria. Perhaps the urge of music-lovers to invest the preludes and fugues with sacred symbols and see them through a religious prism is Bach’s greatest achievement above all.
 In the stricter post-Bach days of the 19th century, theorist Johann André claimed it derived from the German Fug, meaning rules or regularity, propagating the idea of fugue as academic exercise.
 The variety of fugues classified by theorists before Bach is dizzying: fuga totalis, partialis, ligata, sciolta, propria, impropria, authentica, plagalis, contraria, recta, cancrica, doppia, obliga, composta, incomposta, grave, pathetica, major, minor, etc
 Bach’s treatment of themes especially would contribute incalculably to non-fugal composition, especially in the Classical era. For him the themes were not just ideas to be imitated by other voices, but were organically linked to all of the musical material surrounding; one or two ideas in effect became the seeds of all the music in their particular fugue. His thoroughness inspired composers like Haydn and Beethoven, who used melodies to formulate accompaniments and determine the structure of their sonata forms.
 There are different ways to achieve this, and Bach’s method of tuning is not known for certain. Recent scholarship has suggested that a curious drawing on the title page of WTC Book I, a series of interlocked loops, which when deciphered indicate how certain fifths are to be tempered.
 A historical choice that created consensus for 300 years, until Arnold Schoenberg condemned the primacy of the octave and opened the door to twelve-tone music.
 In his obituary for his father, CPE Bach wrote, "He needed to have heard any theme to be aware - it seemed in the same instant - of almost every intricacy that artistry could produce in the treatment of it.”