The Well-Tempered Clavier (WTC) is considered one of the most important keyboard compositions in the context of Western European art music. Bach wrote preludes and fugues in all twenty-four keys, starting with C Major and C minor, moving chromatically up the keyboard to C#, D, etc., all the way to B minor. Bach originally performed this compositional exercise in 1722 and did it again twenty years later.
The title refers to the precursor to the modern tuning system, which took considerable time to develop. I’ve admittedly never understood the finer details, but something about how soundwaves, octaves, and fifths interact is challenging. In any event, eventually people figured out a way to tune the entire keyboard in such a way that all twenty-four major and minor keys could be played without any one key sounding horrendously out of tune. The title of this work is a nod to how, in this well-tempered tuning system, one wouldn’t have to re-tune the keyboard occasionally while cycling through works in every key.
The core impetus for the WTC grew out of pedagogical exercises Bach wrote for his sons who were to take up the mantle of the musical craft. This project eventually grew into the systematic work we have today. The WTC’s original legacy was as a compositional tour de force, and it was studied primarily from that perspective. While the preludes have more freedom than the fugues, both pieces follow the contrapuntal conventions of the time (which are complex and you can read more about them elsewhere).
These pieces eventually became part of the standard repertoire that virtually every piano student encounters. Playing Bach demands that you hold multiple melodic lines in your mind at once and helps develop a student’s hand independence, along with the ability to think horizontally about a score. But considering the regularity with which these pieces are learned, they are performed much less frequently.
One aspect of the WTC I think is often overlooked is its technical virtuosity. When virtuosity comes up with regard to Bach, it’s most often in reference to his compositional mastery — which, admittedly, shouldn’t be downplayed. However, I don’t think we necessarily appreciate how frequently Bach used the extremes of the keyboards he had available at the time. Throughout the WTC, he routinely traverses the entire range of his instrument, and occasionally even writes beyond what we consider the ‘standard range’ for Baroque music. The phenomenon of writing at the extremes of the keyboard is discussed frequently with Beethoven — one can trace the development of the expanded keyboard range in his piano sonatas, as he frequently reached up to the extreme highs and lows of the keyboard. The standard keyboard range expanded in Beethoven’s lifetime, and we can see that development written into his piano compositions. Bach was several generations older than Beethoven. At the end of his life, the very first fortepianos were being built in Italy. I wonder if he had been writing music contemporaneously with Beethoven we would have seen a similar phenomenon emerge.
I also find that the WTC foreshadows some formal conventions that would take hold during the Classical era. In particular, I think we see early hints of a proto-sonata form, as well as the conception of multi-movement works as cohesive sets (as opposed to individual movements that happen to be paired together). In the preludes, there are just a few examples of an early sonata form as is typically imagined, emerging out of rounded binary form (A:||BA:||). The B-flat Major prelude is one of those examples. But in many of the other preludes, ABA is a common formal choice, during which the material in the B section wanders pretty far afield, harmonically speaking, and the A section clearly marks a thematic return that will lead us back to the tonic, or home key. Good examples of this form are the C Major and C# minor preludes. To me, the two key characterics that mark a sonata form are the development section which leads us away from the initial harmonic/melodic material and the moment of recapitulation, where the initial material reasserts itself. That particular sequence of events happens fairly frequently in this volume and makes me question the standard narrative that Bach simply perfected existing musical conventions of the time. He may have been more forward-thinking than we typically give him credit for.