Arab tone system

The modern Arab tone system, or system of musical tuning, is based upon the theoretical division of the octave into twenty-four equal divisions or 24-tone equal temperament, the distance between each successive note being a quarter tone (50 cents).

[4] The specific notes used in a piece will be part of one of more than seventy modes or maqam rows named after characteristic tones that are rarely the first tone (unlike in European-influenced music theory where the tonic is listed first).

The rows are heptatonic and constructed from augmented, major, neutral, and minor seconds.

[5] The current tone system is derived from the work of Farabi (d. 950 CE) (heptatonic scales constructed from seconds), who used a 25-tone unequal scale (see tetrachord), and Mikha'il Mishaqah (1800–1888) who first presented the 24-tone equal-tempered division.

[6] Some strict traditionalists and musicians also use a 17-tone set, rejecting the 24-tone division as commercial.