Microtones and Tuning
Microtones & Tuning
One of the most distinctive and initially challenging aspects of Arabic music for listeners trained in Western equal temperament is its use of microtones — intervals smaller than the Western semitone. Far from being imprecise or “out of tune,” these microtonal intervals are precisely defined, consistently used, and central to the expressive identity of the Arabic musical system.
The Quarter-Tone System
Arabic music is most commonly described using a 24-note octave division, with each semitone divided into two equal quarter tones. This gives a vocabulary of 24 pitches per octave, compared to 12 in Western equal temperament.
The key microtonal pitches are:
Half-flat (♭½)
A pitch lowered by one quarter tone from its natural position. The most common microtonal pitch in Arabic music. Notated in Arabic music with a reversed flat sign or a flat with a slash.
Half-sharp (♯½)
A pitch raised by one quarter tone. Less common but appears in several maqamat. Notated with a half-sharp symbol.
The most important microtonal pitches in practice:
Defines Jins Rast and Maqam Sikah. Between E♭ and E♮ — neither major nor minor.
Part of Jins Rast. Between B♭ and B♮ — gives Rast its characteristic “open” quality.
Defines Jins Bayati above C. The quarter-flat second degree is the soul of Bayati.
Natural Tuning vs. Equal Temperament
Historical Arabic music theory did not use equal temperament. The classical theorists described intervals using ratios derived from the harmonic series and from string divisions. The quarter-tone system adopted in the 20th century (particularly after the 1932 Cairo Congress on Arab Music) is a practical approximation — a framework for discussion and notation, not a rigid prescription for performance.
In living performance practice, pitches are not fixed to exact mathematical values — particularly neutral intervals, which may vary by region, school of playing, and individual performer. A Syrian oud player and an Egyptian one may place the neutral third at slightly different pitches, and both are considered correct within their traditions. This flexibility is not a weakness of the system but one of its great strengths: it allows for regional expression, personal voice, and context-sensitive intonation.
Some modern scholars and performers advocate a return to just intonation or Pythagorean-based tuning systems, arguing that the 24-equal-quarter-tone model flattens the subtle pitch shadings that give Arabic music its distinctive beauty. Others find the 24-tone framework a practical and useful approximation. This is an active area of discussion in Arabic musicology.
The 1932 Cairo Congress
A landmark event in Arabic music history: the International Congress of Arab Music convened in Cairo in 1932, attended by musicians, theorists, and ethnomusicologists from across the Arab world and Europe (including Béla Bartók and Paul Hindemith). One of its central debates was the standardization of the maqam system and tuning.
The Congress adopted a 24-equal-division octave as a practical reference framework, while acknowledging that living practice was more fluid. It also standardized terminology, documented regional variations, and produced recordings of musicians from many countries — an invaluable ethnographic record. The Congress’s decisions remain influential but also contested: some scholars argue that imposing a 24-tone grid distorted subtle regional tuning practices, while others view it as an essential step toward preservation and pedagogy.
Comparison: Western vs. Arabic Interval Systems
| Interval Name | Western 12-TET (semitones) | Arabic 24-TET (quarter tones) | Notes |
|---|---|---|---|
| Unison | 0 | 0 | Same in both systems |
| Quarter tone | — | 1 | Does not exist in Western system |
| Semitone (half step) | 1 | 2 | Same pitch, different count |
| Neutral second | — | 3 | ¾ tone — key to Rast, Bayati, Sikah |
| Whole tone | 2 | 4 | Same pitch |
| Neutral third | — | 7 | Between minor and major third |
| Major third | 4 | 8 | Same pitch |
| Perfect fourth | 5 | 10 | Same pitch |
| Augmented second | 3 | 6 | Defines Jins Hijaz |
| Perfect fifth | 7 | 14 | Same pitch |
| Octave | 12 | 24 | Same pitch |
Microtones on Different Instruments
Oud
Naturally fretless; the player produces microtones through left-hand finger placement on the neck. The oud is the most microtonal-capable Arabic instrument, with infinite pitch resolution limited only by the player’s ear and technique.
Violin / Viola
Used unfretted (as in Western practice); easily produces all microtonal intervals. The violin was adopted enthusiastically into Arabic music precisely because of this flexibility.
Nay (Flute)
Produces microtones through embouchure adjustment and partial fingering. The nay’s breathy tone is naturally suited to the subtle pitch shadings of Arabic music.
Qanun
Has tuning levers (mandals) — small flap-like mechanisms under each string course — that allow the player to raise or lower individual strings by quarter tones during performance. This ingenious system gives the qanun real-time microtonal flexibility.
Accordion / Keyboard
Historically problematic for Arabic music due to fixed equal-tempered tuning. Some Arabic accordions have been specially modified with additional reeds. The piano is generally used only in maqamat that avoid neutral intervals (Nahawand, Ajam, Kurd).
Intonation and Expressive Flexibility
Microtonal flexibility is an expressive resource, not merely a technical requirement. The exact placement of a half-flat pitch is part of the individual performer’s voice and the emotional language of a specific maqam. A singer may slide into a neutral third from below, arriving at it gradually rather than hitting it precisely — this zalagha (glide) is an expressive gesture, not a technical imprecision.
Vibrato depth on a neutral note, the speed of approach to a microtonal pitch, and the degree of pitch bending at phrase endings are all part of the Arabic musician’s expressive palette. Two performers playing the same maqam may place certain pitches at slightly different points in the microtonal spectrum, and both performances may be considered beautiful and correct. The system is precise but not rigid — it breathes.
The Theoretical Foundations
The history of Arabic tuning theory spans a millennium of mathematical and musical inquiry:
The earliest systematic Arabic music theorist. His treatises applied Greek tetrachord theory to Arabic musical practice, establishing the conceptual vocabulary that all subsequent theorists would use and refine.
Described a 17-note octave based on Pythagorean ratios in his monumental Kitab al-Musiqa al-Kabir. His system captured neutral intervals as mathematically distinct pitches — not approximations but precisely defined ratios.
Refined the interval system further, describing neutral intervals as mathematically distinct from any Western ratio. His work in the Shifa connected music theory to philosophy and medicine.
Developed the 17-note system that became foundational for later Ottoman and Arabic theory. His Risala al-Sharafiyya was the standard reference for centuries and influenced Turkish makam theory profoundly.