The modern Arab tone system, or system of This page is about musical systems of tuning, for the musical process of tuning see tuning. ...musical tuning, is based upon the theoretical division of the For the numerical computation software, see GNU Octave. ...octave into twenty_four equal divisions or 24_tone Equal temperament is a scheme of musical tuning in which the octave is divided into a series of equal steps (equal frequency ratios). ...equal temperament, the distance between each successive This article is about music. ...note being a A quarter tone is an interval half as wide (aurally, or logarithmically) as a semitone, which is half a whole tone. ...quarter tone (50 The cent is a unit in a logarithmic scale of relative pitch or intervals. ...cents). Each This article is about music. ...tone has its own name not repeated in different octaves (lacking For the numerical computation software, see GNU Octave. ...octave equivalency). The lowest tone is named yakah and is determined by the lowest In music, pitch is the perception of the frequency of a note. ...pitch in the range of the singer. The next higher octave is nawa and the second tuti. (Touma 1996, p.17_18) However, from these twenty_four tones seven are selected to produce a scale and thus the interval of a quarter tone is never used and the three_quarter tone or medium second should be considered the characteristic interval. (ibid, p.23)

The system is written in European Music notation is a system of writing for music. ...musical notation using a slashed flat for quarter flat, a flat for half-tone Alternate uses: Flat (disambiguation) Figure 1. ...flat, a slashed flat and a flat for three-quarter tone flat, sharp with one vertical line for quarter sharp, sharp (#) for half-step This article is about the musical notation. ...sharp, and a half sharp and a sharp for three-quarter sharp. A two octave range starting with yakah arbitrarily on the G below middle C is used. (ibid, p.24)

In practice far fewer than twenty-four tones are used in a single performance. All twenty-four tones are individual pitches differentiated into a A hierarchy (in Greek hieros = sacred, arkho = rule) is a system of ranking and organizing things. ...hierarchy of important pitches, "pillars", which occur more frequently in the tone rows of traditional music and most often begin tone rows, and scattered less important or seldom occurring pitches (see Tonality is the character of music written with hierarchical relationships of pitches, rhythms, and chords to a center or tonic. ...tonality). (ibid, p.24_25).

The specific notes used in a piece will be part of one of more than seventy This article is about modes as used in music. ...modes or In music, a maqam [sic] (plural maqamat) is a technique of improvisation that defines the pitches, patterns, and development of a piece of music. ...maqam rows named after characteristic tones which are rarely the first tone (unlike in European_influenced music theory where the Tonic may mean: A concept from musical harmony and musical theory: see Tonic (music); A carbonated beverage flavoured with quinine, used in cocktails: see Tonic water. ...tonic is listed first). The rows are heptatonic and constructed from The musical interval of a minor third is the relationship between the first note (the root or tonic) and the third note in a minor scale. ...augmented, The musical interval of a major second — also called a whole_tone — is the relationship between the first note (the root or tonic) and the second note in a major scale (and also a minor scale). ...major, medium, and The musical interval of a half step, semitone, or minor second is the relationship between the leading tone and the first note (the root or tonic) in a major scale. ...minor seconds. Many different but similar ratios are proposed for the frequency ratios of the tones of each row and performance practice has, as of 1996, has not been investigated using electronic measurements. (ibid, p.18) Actual practice is estimated to vary within a quarter tone from notation.

The current tone system is derived from the work of Al Farabi (870_950) was born of a Turkish family and educated by a Christian physician in Baghdad, and was himself later considered a teacher on par with Aristotle. ...al_Farabi (d. 950 CE) (heptatonic scales constructed from seconds) who used a 25 (unequal) tone scale (see In musical theory, a tetrachord is a series of four diatonic tones encompassing the interval of a perfect fourth. ...tetrachord), with Mikha'il Mishaqah (1800-1889) first presenting the 24 tone equal tempered division. (ibid, p.19)

Source

• Habib Hassan Touma (1996). The Music of the Arabs, trans. Laurie Schwartz. Portland, Oregon: Amadeus Press. ISBN 0931340888.