Johann Sebastian Bach never completed The Art of Fugue, BWV 1080. It is a collection of contrapuntal movements with no definite order of presentation or instrumentation. Movements have been added and taken away from the final score over the years. Since the revival of popular interest in Bach's music in the 1850s, historians have narrowed the margin of error regarding the history and performance of The Art of Fugue with impressive efficiency. What is certain is that it is among the most gripping instrumental works that exists, demonstrating practically every composing technique available to Bach.

The work was among his estate; he probably did not discuss the work with anyone, or there would have been more pressure to have its mysteries settled before his passing. His son, Carl Philipp Emmanuel, found and published the work as he found it in 1751, still incomplete. It did not sell well. Originally it was thought that Bach had been working on it and died in a race to finish it. Research has proven that he began the piece in the early 1740s (he died in 1750) and returned to work on it further over the years. It has also intrigued alert listeners to hear the final, unfinished movement trail off with B flat, A, C, B natural, which in German musical terminology translates to the word "BACH." This poignant accident of history has done wonders for the general interest in the piece, though in its day the public considered this just shoddy, and C.P.E. Bach attempted to compensate purchasers with the inclusion of a well-known chorale prelude, which was not related to the rest of the work.

Listening to The Art of Fugue is hearing everything available to the composer of fugues, woven together better than any other composer has done, and rife with a sublime poetic energy. Throughout the twentieth century, a tenuously agreed upon arrangement of 22 movements makes up a most likely reliable incarnation of what the composer had in mind. It is slightly longer than 80 minutes in duration and alternates between keyboard and small ensemble as required. Most of it can be played on the keyboard, but exact instrumentation was not necessarily as specific in the early eighteenth century as it would be later on. The theme is not obscured at any point, though he sometimes reverses it, turns it upside down, or both, or combines these variations with the theme's original form, all performed concurrently. Simply writing a good canon takes skill, and what Bach manages with The Art of Fugue cannot be matched by anything in this regard, except perhaps a few of his other works, such as The Musical Offering. In spite of the technical/theoretical maelstrom The Art of Fugue leaves for scholars to wade into, there is nothing about its character to deter the casual listener. The opposite is true; it is almost impossible to find a more benevolent piece of music. One can listen to it for years with only a casual grasp of the greatness that lays amid the scintillating arabesques that pervade the material. Once entered into the world of this work, it will gradually reveal itself to maintain potency greater than most people expect music to be able to contain.

Source: AllMusic (http://www.allmusic.com/composition/die-kunst-der-fuge -the-art-of-the-fugue-for-keyboard-or-other-instruments -bwv-1080-mc0002368456).

Although originally written for keyboard, I created this Arrangement of the Contrapunctus III (BWV 1080 No. 3) for String Quartet (2 Violins, Viola & Cello).