Arab tone system
Encyclopedia
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
(24-TET), the distance between each successive note being a quarter tone
(50 cents
). Each tone has its own name not repeated in different octaves, unlike systems featuring octave equivalency. The lowest tone is named yakah and is determined by the lowest pitch
in the range
of the singer. The next higher octave is nawa and the second tuti. 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 neutral second
should be considered the characteristic interval.
By contrast, in the European equally tempered scale
the octave is divided into twelve equal divisions, or exactly half as many as the Arab system. Thus the system is written in European musical notation
using a slashed flat for quarter flat (some systems use a reversed flat sign instead), a flat for half-tone flat, a slashed flat and a flat for three-quarter tone flat, sharp with one vertical line for quarter sharp, sharp (♯) for half-step 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.
In practice far fewer than twenty-four tones are used in a single performance. All twenty-four tones are individual pitches differentiated into a hierarchy
of important pitches, "pillars", which occur more frequently in the tone row
s of traditional music and most often begin tone rows, and scattered less important or seldom occurring pitches (see tonality
).
The specific notes used in a piece will be part of one of more than seventy mode
s or maqam rows named after characteristic tones which 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 second
s. Many different but similar ratios are proposed for the frequency ratios of the tones of each row and performance practice, as of 1996, has not been investigated using electronic measurements. Actual practice is estimated to vary within a quarter tone from notation.
The current tone system is derived from the work of al-Farabi
(d. 950 CE) (heptatonic scales constructed from seconds) who used a 25 (unequal) tone scale (see tetrachord
), with Mikha'il Mishaqah (1800-1889) first presenting the 24 tone equal tempered division.
Musical tuning
In music, there are two common meanings for tuning:* Tuning practice, the act of tuning an instrument or voice.* Tuning systems, the various systems of pitches used to tune an instrument, and their theoretical bases.-Tuning practice:...
, is based upon the theoretical division of the octave
Octave
In music, an octave is the interval between one musical pitch and another with half or double its frequency. The octave relationship is a natural phenomenon that has been referred to as the "basic miracle of music", the use of which is "common in most musical systems"...
into twenty-four equal divisions or 24-tone equal temperament
Equal temperament
An equal temperament is a musical temperament, or a system of tuning, in which every pair of adjacent notes has an identical frequency ratio. As pitch is perceived roughly as the logarithm of frequency, this means that the perceived "distance" from every note to its nearest neighbor is the same for...
(24-TET), the distance between each successive note being a quarter tone
Quarter tone
A quarter tone , is a pitch halfway between the usual notes of a chromatic scale, an interval about half as wide as a semitone, which is half a whole tone....
(50 cents
Cent (music)
The cent is a logarithmic unit of measure used for musical intervals. Twelve-tone equal temperament divides the octave into 12 semitones of 100 cents each...
). Each tone has its own name not repeated in different octaves, unlike systems featuring octave equivalency. The lowest tone is named yakah and is determined by the lowest pitch
Pitch (music)
Pitch is an auditory perceptual property that allows the ordering of sounds on a frequency-related scale.Pitches are compared as "higher" and "lower" in the sense associated with musical melodies,...
in the range
Vocal range
Vocal range is the measure of the breadth of pitches that a human voice can phonate. Although the study of vocal range has little practical application in terms of speech, it is a topic of study within linguistics, phonetics, and speech and language pathology, particularly in relation to the study...
of the singer. The next higher octave is nawa and the second tuti. 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 neutral second
Neutral second
A neutral second or medium second is a musical interval wider than a minor second and narrower than a major second. Three distinct intervals may be termed neutral seconds:...
should be considered the characteristic interval.
By contrast, in the European equally tempered scale
Equal temperament
An equal temperament is a musical temperament, or a system of tuning, in which every pair of adjacent notes has an identical frequency ratio. As pitch is perceived roughly as the logarithm of frequency, this means that the perceived "distance" from every note to its nearest neighbor is the same for...
the octave is divided into twelve equal divisions, or exactly half as many as the Arab system. Thus the system is written in European musical notation
Musical notation
Music notation or musical notation is any system that represents aurally perceived music, through the use of written symbols.-History:...
using a slashed flat for quarter flat (some systems use a reversed flat sign instead), a flat for half-tone flat, a slashed flat and a flat for three-quarter tone flat, sharp with one vertical line for quarter sharp, sharp (♯) for half-step sharp
Sharp (music)
In music, sharp, dièse , or diesis means higher in pitch and the sharp symbol raises a note by a half tone. Intonation may be flat, sharp, or both, successively or simultaneously...
, 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.
In practice far fewer than twenty-four tones are used in a single performance. All twenty-four tones are individual pitches differentiated into a hierarchy
Hierarchy
A hierarchy is an arrangement of items in which the items are represented as being "above," "below," or "at the same level as" one another...
of important pitches, "pillars", which occur more frequently in the tone row
Tone row
In music, a tone row or note row , also series and set, refers to a non-repetitive ordering of a set of pitch-classes, typically of the twelve notes in musical set theory of the chromatic scale, though both larger and smaller sets are sometimes found.-History and usage:Tone rows are the basis of...
s of traditional music and most often begin tone rows, and scattered less important or seldom occurring pitches (see tonality
Tonality
Tonality is a system of music in which specific hierarchical pitch relationships are based on a key "center", or tonic. The term tonalité originated with Alexandre-Étienne Choron and was borrowed by François-Joseph Fétis in 1840...
).
The specific notes used in a piece will be part of one of more than seventy mode
Musical mode
In the theory of Western music since the ninth century, mode generally refers to a type of scale. This usage, still the most common in recent years, reflects a tradition dating to the middle ages, itself inspired by the theory of ancient Greek music.The word encompasses several additional...
s or maqam rows named after characteristic tones which are rarely the first tone (unlike in European-influenced music theory where the tonic
Tonic (music)
In music, the tonic is the first scale degree of the diatonic scale and the tonal center or final resolution tone. The triad formed on the tonic note, the tonic chord, is thus the most significant chord...
is listed first). The rows are heptatonic and constructed from augmented
Augmented second
In classical music from Western culture, an augmented second is an interval produced by widening a major second by a chromatic semitone. For instance, the interval from C to D is a major second, two semitones wide, and both the intervals from C to D, and from C to D are augmented seconds, spanning...
, major
Major second
In Western music theory, a major second is a musical interval spanning two semitones, and encompassing two adjacent staff positions . For example, the interval from C to D is a major second, as the note D lies two semitones above C, and the two notes are notated on adjacent staff postions...
, neutral
Neutral second
A neutral second or medium second is a musical interval wider than a minor second and narrower than a major second. Three distinct intervals may be termed neutral seconds:...
, and minor second
Minor second
In modern Western tonal music theory a minor second is the interval between two notes on adjacent staff positions, or having adjacent note letters, whose alterations cause them to be one semitone or half-step apart, such as B and C or C and D....
s. Many different but similar ratios are proposed for the frequency ratios of the tones of each row and performance practice, as of 1996, has not been investigated using electronic measurements. Actual practice is estimated to vary within a quarter tone from notation.
The current tone system is derived from the work of al-Farabi
Al-Farabi
' known in the West as Alpharabius , was a scientist and philosopher of the Islamic world...
(d. 950 CE) (heptatonic scales constructed from seconds) who used a 25 (unequal) tone scale (see tetrachord
Tetrachord
Traditionally, a tetrachord is a series of three intervals filling in the interval of a perfect fourth, a 4:3 frequency proportion. In modern usage a tetrachord is any four-note segment of a scale or tone row. The term tetrachord derives from ancient Greek music theory...
), with Mikha'il Mishaqah (1800-1889) first presenting the 24 tone equal tempered division.