He starts with relatively basic fugues, as described above, then steadily escalates the complexity, meanwhile ornamenting and varying the AOF theme itself. So Contrapuncti 1-4 are straightforward, except that in the second two, the AOF theme is inverted, meaning every melodic move up becomes an equivalent one down, and vice versa. In Contrapunctus 5 the ornamented subject enters both upside-down and right-side-up. From there, we tune in to the major leagues of fuguedom. In Contrapunctus 6, the first voice is the regular (ornamented) AOF subject, the second voice is the subject inverted, the third voice is the subject right-side-up, the fourth voice is the subject inverted—except entries two through four present the subject at double speed. By Contrapunctus 7, the AOF theme is going at three speeds, variously rightside up and inverted—with a nice effect, in this performance by the Musica Antiqua Köln, of nervous intensity.
Contrapunctus 9 is maybe the most familiar of the bunch thanks to the Swingle Singers, who turned it into a scat-sung hit in the '60s. This one takes a different tack: A fugue on a racing, jazzy new subject bops along in three voices for a while before the AOF theme is laid on top of it.
Let's compare three versions of No. 9. Here's Aimard. In this version by the early-music ensemble Hespèrion XXI, we'll put it ahead so you hear how the AOF theme is laid over the new subject —it's in the thing that sounds like a trumpet (which is a Renaissance cornett). And now the old Swingle Singers version, of which I'm still fond for nostalgic reasons. (Schlock is in the eye of the beholder.)
By Contrapuncti 12 and 13 we're in Alice in Wonderland territory: The entirety of both fugues is presented right-side-up and mirrored—i.e., upside down—and they all sound perfectly swell.
Bach was playing these otherworldy games when fate stepped in: He went blind and soon died. (On his deathbed, he dictated a haunting organ prelude called Before Thy Throne I Stand, as his calling card to God.) The unfinished last fugue in the AOF was intended to weave together four different subjects. He only got to the third one, which happened to be his own name. In German notation, B means B-flat and H means B-natural, so he could spell out B-A-C-H in notes. Composers ever since have used the motif as a homage. Aimard's version, like many others, rises to a spine-tingling peroration on the B-A-C-H motif, proclaimed over and over, when the music suddenly stops in the middle of a phrase just as Bach himself did. Here's Aimard near the conclusion of the unfinished one, where the B-A-C-H subject entries start.
So there you have the makings of an unlikely hit. Meanwhile an Emerson String Quartet recording of fugues from Bach's Well-Tempered Clavier has been sharing the Billboard top 10 with Aimard's recording. Is there some musical millennium at hand? Has the '60s generation finally started to grow up, musically and otherwise?
Nah. My generation will boogie to our graves, our tastes in music and much else still adolescent, still thinking we're cool as hell. The truth is I have no idea why Bach fugues have all this buzz. The Billboard classical charts are dominated by schlock, but the Aimard and Emerson recordings are one of those ever-surprising cases of uncompromising work making a hit in the commercial funhouse we call our "culture."
Even schlock Bach isn't unredeemable. His music tends to work in all versions, I submit, because the notes-qua-notes are so good. Mozart, Beethoven, Stravinsky, or [your favorite composer here] were constantly concerned with the instruments that played or sung their work: great notes, too, but intimately bound to their media. In TheArt of Fugue Bach didn't seem to care what the medium was; it would work no matter what. A lot of his music—not all, but a lot—is like that: incomparable notes, regardless of avatar.
I'm sure what ultimately turns everybody onto TheArt of Fugue, not limited to musicians who understand its arcana, is how melodically expressive and rhythmically vital it is. You never forget, for example, how Contrapunctus 9 gathers like a force of nature from a galloping D minor to the most hair-raising D major final chord you ever heard. Bach universalized what he called "the art and science of music" by the power of gripping melody, rich harmony, towering perorations, intimate whisperings, explosive joy, piercing tragedy: the same human stuff we find in Beethoven, Mozart, Shakespeare, and all the great creators. But nobody in music had the science down more than Bach did, and nobody ever wrote better notes.