A capable violinist and thoroughly familiar with trend-setting Italian models, Bach undoubtedly wrote much more chamber music than has come down to us. He was not, however, much attracted to the then-dominant trio sonata form, written for two solo instruments with continuo accompaniment (improvisation over a notated bass line, usually by harpsichord or lute, with the appropriate chords indicated).

On the one hand, he favored the solo sonata without accompaniment, composing a group of six sonatas and partitas for violin, six suites for cello, and a sonata for flute, all of which are astonishing accomplishments of contrapuntal and idiomatically instrumental art. Another type of duo sonata, which he virtually created, leaned the other way, toward a more controlled version of the trio sonata texture. Bach manipulated and merged conventional forms and genres with uncommon flexibility. The six sonatas for violin and harpsichord that he wrote liberated the keyboard from the filler functions of continuo accompaniment, creating true partnership with the solo violin. In those sonatas, the right hand of the keyboard part replaces the second solo part of the trio sonata, over an active bass line that also participates in the polyphonic give-and-take.

This is readily apparent throughout the Sonata in E, No. 3 of the set, as the violin and keyboard parts swap material back and forth in buoyant counterpoint. Less obvious is Bach’s subtle skill at thematic transformation and motivic development, to use terms usually applied only to much later music, and his moments of pulse-defying syncopation and metrical shifts.

The structure of the sonata is that of the old Italian sonata da chiesa, or church sonata – four movements, slow-fast-slow-fast. The fast movements are basically abstracted dances, with three-part imitation as the main ideas are passed around between the violin and the right and left hands of the keyboard part. The slow movements function as lyrically poised preludes.

- John Henken is the Director of Publications for the Los Angeles Philharmonic Association.