Oud later), tuned in successive fourths. Curt Sachs said they were called (from lowest to highest pitch) "bamm", "maṭlaṭ", "maṭnā" and "zīr". "As early as the ninth century" a fifth string "ḥād" ("sharp") was sometimes added "to make the range of two octaves complete". It was highest in pitch, placed lowest in its positioning in relation to other strings. Modern tuning preserves the ancient succession of fourths, with adjunctions (lowest or highest courses) which may be tuned differently following regional or personal preferences. Sachs gives one tuning for this arrangement of five pairs of strings, d, e, a, d', g'. Historical
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