During his long life, Bach must have written and improvised thousands of fugues. For any occasion (secular or sacred), for any instrumentation (be it a single instrument or large ensemble), for compositions with or without text, the fugue was for him an invaluable vehicle to give shape to his inexhaustible inspiration. Was his musical output already an art of fugue by it's compass and nature, his mastery and control over this form found it's synthesis in a work called The Art of Fugue, or as it's title reads in German: Die Kunst der Fuge. In this work Bach grouped together fugues and canons, all based on one theme. As such it stands next to other great mono-thematic works like the Goldberg Variations, Musikalisches Opfer and Einige Canonische Veränderingungen. Since Die Kunst der Fuge was published one year after Bach's death, the work is often connected with the last years of his life. A closer study of the history of the work reveals, however, a long genesis.In counterpoint studies written by Wilhelm Friedemann Bach and corrected by his father in the mid thirties of the 18th century, we find the first traces of the the-art-of-fugue-theme. During these years Bach developed more complex techniques of fugal writing in pieces he used for the 2nd part of Das wohltemperierte Klavier. In Die Kunst der Fuge, Bach combines the use of one theme for several fugues and canons and the complex techniques of fugal writing in a new work. Could his contemporary and colleague Johann Mattheson have challenged him to do so? In his book, Der Vollkommene Capellmeister (1739!), we find the following remark: 'Of double fugueswith three subjects, there is, as far as I know, nothing else in print but my own work... which I, out ofmodesty, would comment to no one. On the contrary, I would much rather see something of the same sort published by the famed Herr Bach in Leipzig, who is a great master of the fugue'. The appearance of a manuscript with the title 'Die Kunst der Fuga' (a title not written in Bach's handwriting but in that of his son in law, Johann Christoph Altnickol), of which the beginnings date from the early forties, maybe1742, does not exclude a connection between the two works. The relation between the two works is more apparent in Bach's use of the name Contrapunctus, for every single fugue. Mattheson applies the term exclusively to fugues and defines it literally as 'Gegensatz', a melody set against a theme ('Punkt' or 'Satz'). In this, the main attention of the content of the pieces shifts from the fugue as a form to it's contrapuntal procedure. But the work was not finished with the completion of the manuscript. It may have even been so that, writing the fair copies of the last contrapuncti, Bach started to revise fugues that were already written out in the manuscript. By 1746 (the last section of the manuscript is written on paper dating from that year) the final copy was turned again into a rough draught. And if we compare the manuscript with the printed version (1751), the various differences indicate that Bach altered nearly all aspects of the work during the last years of the decade. He added new contrapuncti, recomposed others, changed the metre of some and rearranged them in a different order. At the same time he wrote a great many of the Abklatschvorlagen, the sheets that served as a model on which the engraver could prepare the copper plates from which the work was printed. The intense work for the preparation of the print came to an end when Bach became ill. An eye-illness took his sight, surgery failed and may have hastened his death. Since the printing of Die Kunst der Fuge was completed after Bach's death, the chaotic nature of the 1751 print indicates that his intentions may not have been fully realised. The content of the print seems to reflect Bach's intentions up and till the three-part mirror-fugues. Under Bach's guidance, the following compositions would not have been printed: an earlier version of Contrapunctus 10, the transcription of the three-part mirror-fugue in a version for two harpsichords, and the Choral Wenn wir in Hoechsten Noethen. Furthermore, the canons would have been placed in the correct order. Lastly, the unfinished fugue, Fuga a tre soggetti, would not have been taken into account as belonging to the cycle. Or, if it was Bach's intention to add such a piece, the correct version of the fugue, if any existed at all, would have been printed. This recording contains the various parts of Die Kunst der Fuge that can be considered as belonging to the work without question. They are played in the order that most likely reflects Bach's intentions, an order that shows wonderful mirror structures on different levels. The version for 2 harpsichords (BWV 1080/18) is chosen to interpret the three-part mirror-fugues, because it reflects how it was performed in Bach's circle. The four-part mirror-fugue could easily be performed on two harpsichords using the original score. One of the marvels of the fugues and canons of Die Kunst der Fuge is that, notwithstanding their complexity, they can be performed by two hands on one keyboard. Considering Die Kunst der Fuge in the tradition of Das wohltemperierte Klavier, performance on the harpsichord is most convincing. Numerous places of idiomatic writing point in the same direction as do considerations with regard to the tessitura. The writing of keyboard polyphony in four-stave score stands in the tradition of composers such as Frescobaldi and Froberger. Paying respect to the above mentioned explanation of the title Contrapunctus of each piece, the sequence of fugues is performed as a suite: a set of character pieces in which the affect of every single piece is constituted by the nature of the used contrapuntal devices. The harpsichord used in this recording (kindly placed at our disposal by Jeroen Heijungs) was built in 2002 by Jan Kalsbeek, Zutphen, Holland. It is based on a two-manual harpsichord made by Michael Mietke in Berlin ca. 1700. This instrument is located in Schloss Charlottenburg in Berlin. It is strung throughout in brass and has a compass of FF - f'''. Items 12 - 15 are played on two harpsichords, the second one is played by Alessandro Santoro. For this we used a similar instrument, but this time strung in iron, like the original is now, after a ravalement in the 18th century. Albert-Jan Roelofs.