Contrapunctus IX, “alla duodecima,” from The Art of the Fugue, BWV 1080

by Max Derrickson

Johann Sebastian Bach
(Born in Eisenach, Germany in 1685; died in Leipzig, Germany in 1750)

Contrapunctus IX, “alla duodecima,” from The Art of the Fugue, BWV 1080

As Bach’s life entered into its last decade, he renewed his interest in keyboard music and especially counterpoint, or the way in which fugues are made and how musical themes can be manipulated.  In this decade he began his ultimate offering to musical counterpoint – a series of fugues and canons all derived out a single musical theme – The Art of the Fugue, which he worked on for 10 years until his death, but left incomplete for it to be gathered, titled and published in 1751just after his death by his son Carl Phillip Emmanuel Bach.

The Art of the Fugue may well be Bach’s seminal work and contains 14 fugues and four canons, all in D-minor, and arranged in increasing difficulty.  They are, as Bach historian Christoph Wolff observed, “an exploration … of the contrapuntal possibilities inherent in a single musical subject.”  That “single subject” is disarming in its simplicity but is a gold mine for Bach’s 18 forays into forging musical matter.  Instead of calling them “counterpoint(s),” Bach preferred the Latin word “Contrapunctus.”  Number IX (9) is a study of turning that simple subject into a new derivation and into a double fugue (two themes treated as a fugue at the interval of a twelfth, thus the subtitle “alla duodecima”).  Bach then adds the original “single subject” fugue theme into the mix as an additional subject.  Always a masterpiece, this Contrapunctus becomes especially spirited and extremely powerful when performed by a brass quintet.