Pre-Islamic Arabia
In Pre-Islamic Arabia and Mesopotamia, the oud had only three strings, with a small musical box and a long neck without any tuning pegs. But during the Islamic era the musical box was enlarged, a fourth string was added, and the base for the tuning pegs (Bunjuk) or pegbox was added. In the first centuries of (pre-Islamic) Arabian civilisation, the oud had four courses (one string per course — double-strings came 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'.