Six Sonatas for Violin and Harpsichord, BWV 1014–1019 alto solo. At first declamatory in the "forte" passages, the "piano" responses are expressive but subdued. Bach's knowledge of the expressive qualities of the violin is shown in the opening phrases, written so they can be played on the G string, the lowest string on the violin, regarded as having a "noble" tone. As explains, citing the opening of BWV 1017/3 as an example, the G string's "energy and powerful voice make it a whole instrument in itself and the lower this voice is, the more opportunity it gives to expression to attain the sublime." Around the violin melody, in
Electric violin to an independent MIDI channel. Most recently, Keith McMillen of Keith McMillen Instruments, a founder of Zeta Music, announced the StringPort polyphonic string-to-USB 2.0 converter for the Zeta polyphonic pickup and other modern polyphonic violin systems. Whilst no other dedicated violin-to-MIDI systems have been manufactured, more generic pitch-to-MIDI systems like those from Roland, and Yamaha can be adapted to use standard electric violin output. Most systems allow only monophonic operation—only one pitch can be detected and digitised at a time—but through the use of proprietary pickups, some limited MIDI polyphony can be achieved. Some pitch to MIDI interfaces from Axon/TerraTec