Four Duets for keyboard

A third installment in the Clavier-Übung series followed rather soon thereafter. As mentioned above, most of the material in Clavier-Übung III is written for organ. Bach, of course, was one of the towering organ virtuosos of all ages. But he also made important contributions to “secondary” aspects of organ technique and instrument design, once again testifying to his abundant curiosity and systematic quest for completeness (embracing the theory and practice of organology). Clavier-Übung III includes a large Prelude and triple Fugue in E-flat (the so-called “St. Anne” pairing), the organ mass consisting of twenty-one chorale preludes, and four duets. These duets do not include a pedal line; hence they are equally suited for performance on harpsichord or piano. In fact, there is on-going discussion about exactly what instrument Bach had in mind when he composed the four works and why they are included here at all. One interpretation posits that Bach included the duets in order to bring the total number of pieces in the collection to a Trinitarian total of 27 = 3x3x3.
The material within these four duets seems equally provocative, for it is highly chromatic and entirely free of chorale references. The first piece, in E minor, moves gradually and chromatically through all manner of two-voice counterpoint, almost in a demonstrative, pedagogical fashion. In F major and da capo ABA form, the second duet is more conventional from the start, bringing to mind portions of Bach's own two-voice Inventions—though the B section reverts to the chromatic idiom of No. 1. Duet No. 3 in G major is the least experimental of the set. To me, it sounds like a prelude to the A-minor fugue which follows as Duet No. 4. This last work includes a lengthy fugue subject and numerous episodes in related keys. Stylistically, the four works seem slightly out of their element in this larger “German Organ Mass,” which makes their inclusion all the more intriguing.

(c) Jason Stell