Bach stopped at the height of his art – but why?

There are works of art whose fame obstructs their proper understanding. Johann Sebastian Bach's "The Art of Fugue" is undoubtedly one of them. First published in 1751, shortly after the composer's death, the work is today admired as "the most substantial, original, and personal instrumental work from Bach's pen" (Christoph Wolff).

Although admired as the last word of the old Bach, it certainly raised questions from the outset: Why does this encyclopedic demonstration of contrapuntal artistry end, seemingly incongruously, with a chorale prelude? What is the hidden logic of its inscrutable structure? And, the most important question of all: Why does the final fugue break off precisely after the point where the musical letters BACH appear in all four voices as the third theme?

The surviving material seemed to provide the first answers. Bach's son, Carl Philipp Emanuel, the lead editor of the posthumous printed edition, wrote in the autograph manuscript he left behind: "NB: The author died above this fugue, where the name BACH was added in the contrasubject." According to this reading, the audience was apparently meant to be compensated for the unfinished state of the last fugue with the aforementioned final chorale. Because Bach had become blind in his final days, he is said to have "dictated it off the cuff to one of his friends."

With the help of so-called paratexts, i.e., editorial notes, an aura is already woven around the printed work. This aura is contributed not only by all the remarks in the preface, but also by the preliminary report to the second edition (1752), signed by Friedrich Wilhelm Marpurg, and the obituary published two years later, in which Carl Philipp Emanuel again participated. According to this, the elderly Bach embarked on a major publication project at the end of his life: It was intended to demonstrate the creation of various fugues (which Bach, in an old-fashioned and rigorous way, called "contrapunctus") and canons from a single, continuously varied theme, literally according to every trick in the book.

He died while working on the final fugue, in which he meaningfully wanted to emphasize his signature. The editors, led by Bach's son, added the chorale prelude "Wenn wir in hochsten Noethen seyn" (When we are in dire need) to the materials already arranged by Bach himself and, in their view, placed the unfinished fugue at the end, before it. The unfinished fugue—more precisely, a triple fugue with the note sequence BACH as the crowning climax in the third theme—was then, without further explanation, further elevated in the preface to the second edition and in the obituary: to the phantom of a quadruple fugue (i.e., with four themes) that was never realized. Perhaps to underscore the fragmentary nature of the work.

So much for the legend. It took root under the editors' careful attention to reception and is still circulated in some cases today. However, Bach scholarship in recent decades has exposed much of this as misinformation and fundamentally corrected it. First of all: The Art of Fugue is by no means Bach's last work. Rather, it was begun around 1742, eight years before his death, and thus marks the beginning, not the end, of Bach's growing obsession with fugue, canon, and variation techniques as he grew older. Furthermore, Bach was involved in the printing process from the very beginning, not least by personally preparing models for the copperplate engraving.

The whole thing is based on a plan developed in several stages, which was spoiled by the posthumous edition. Bach actually envisioned a logic of increasing complexity: from simple fugues (Contrapunctus 1–4) to counter-fuges (5–7: theme and inversion), double and triple fugues (8–11), and finally the balancing act of the so-called mirror fugues, in which the entire musical structure can be rotated around a horizontal axis (12–13).

This is followed by four increasingly complex two-part canons. Their climax is the so-called Augmentation Canon, in which the highly varied theme is followed by its inversion in doubled note values—probably the most spectacular polyphonic adventure of the entire work.

That Bach began to expand his plan towards the end of the 1740s can be deduced from the erased and overwritten page numbers on some printing plates. The executors of the estate failed to adequately understand this, or at least barely took it into account. In Bach's modified layout, which ultimately also included a four-part alternative version for the three-part second mirror fugue, they arbitrarily inserted another fugue (namely, an earlier, discarded stage of Contrapunctus 10) and also placed the unfinished "BACH" triple fugue before the concluding organ chorale.

This arrangement, increasingly illogical in its second half, has caused some confusion among posterity. It has also greatly stimulated research. Today, there are more than 80 proposals for an improved arrangement and, most importantly, more than 30 attempts to complete the fragmentary final fugue.

They are guided by the assumption, fueled by the obituary, that this "Fuga a 3 soggetti" was actually a planned quadruple fugue, whose fourth subject was intended to be the triumphant main theme of the entire cycle. Given that this fugue opens with a variation of the main theme, this seems hardly credible.

In any case, the most illuminating suggestion for solving the puzzle has been available for a year now: in Meinolf Brüser's short monograph "Es ist alles Windhauch," which, for the first time, reconstructs Bach's work conception in all its rigor. Without being able to recount the author's almost criminalistic argumentation in detail here, the following seems clear: If Bach's manuscript of the fugue fragment (on which his son wrote the whispered note of the author's premature demise) breaks off in the middle of the fifth page, this was done intentionally.

Firstly, the rest of the page is unusable for a continuation of the manuscript due to a defective grid of the staves. Secondly, the torso breaks off significantly at bar 239 after the insertion of the "BACH" theme: the sum of this number is 14. But this is nothing other than the numerical symbolic encryption of the author's name (B=2, A=1, etc.). And thirdly, the fragment—even as a torso, one of Bach's longest instrumental fugues—should be placed in the overall plan behind Contrapunctus 13 as the fourteenth fugue before the group of canons.

The printed version of the fugue, shortened by seven bars, is evidently by Bach himself. And at the bottom of the page where it abruptly ends, in one of the breaking parts, a cross-reference mark is provided, precisely at the note "d." This leads to exactly the same note with which the augmentation canon begins on the opposite page of the manuscript. For pragmatic reasons, it is placed at the beginning of the group of four canons, rather than crowning them.

If this was Bach's actual plan, and there is much to suggest this, then the interrupted fugue does not belong at the end, but rather at the center of the work. And its interruption is deliberately staged there. Why? Brüser sees this as a subtle gesture of humility on the part of the older Bach, a retreat of the finite creative subject before his Creator God—precisely at the point at which his own creativity reaches the peak of its combinatorial possibilities. This habitus is well known from the Baroque still-life tradition, with its artists' self-portraits between extinguishing candles and skulls as vanitas symbols. Its staging in a musical work is, of course, unique.

Bach's organ chorale serves as a counterbalance to this anticlimax, which addresses his own finiteness. It concludes the large Leipzig chorale manuscript as a traditional fragment and bears the much more fitting title "Vor dein Thron tret' ich hiermit" (I hereby enter before your throne). However, the editors replaced it with a slightly different earlier version bearing the title "Wenn wir in hoechsten Noethen seyn" (When we are in highest need).

If all this is true, then The Art of Fugue would by no means be a project reduced to a torso by fate, as the legend promulgated by Bach's estate administrators would have it. Rather, the myth of completion being prevented by Bach's death appears to be a posthumous construct. This myth reveals the worldview of a new generation, one that is even closer to us today and seems far more "modern" than the gesture of humility of Bach's original conception, deeply rooted in Baroque piety. It interprets the (supposed) torso character of The Art of Fugue as a visionary anticipation of the fascination with fragments that emerged in the age of Sensibility and spread in early Romanticism.

For all the reverence and admiration paid to the work by posterity, the question of its performability slipped out of focus. For the Schoenberg school in particular, it became the epitome of pure spiritualization. Anton Webern called "The Art of Fugue" a "work that leads completely into the abstract." And Theodor W. Adorno counted it among "the speculative works of the late period," even seeing its dematerialized hermeticism as deliberately "sparing sound."

The young Swiss composer Wolfgang Graeser, however, attempted to demonstrate its performability with an orchestral arrangement as early as 1927 – initially with only moderate success. Only in recent decades have numerous musicians overcome their hesitancy and brought the richness of the work to life in various versions and ensembles. And if, as is to be hoped, the first soloists and ensembles soon dare to perform "The Art of Fugue" in the newly proposed arrangement, then the posthumously published work will probably finally shed its aura of being a kind of greeting from beyond the grave.

Nevertheless, the great sphinx of music history will never lose its enigmatic character. For, like all great art, it is – according to Schelling's beautiful dictum – "capable of infinite interpretation." The effort to understand it will never end.

Hans-Joachim Hinrichsen was Professor of Musicology at the University of Zurich from 1999 to 2018. Between 2001 and 2012, he served, among other roles, as President of the International Bach Society Schaffhausen (IBG).