In Ottoman musical theory, aksak is a rhythmic system in which pieces or sequences, executed in a fast tempo, are based on the uninterrupted reiteration of a matrix, which results from the juxtaposition of rhythmic cells based on the alternation of binary and ternary quantities, as in 2+3, 2+2+3, 2+3+3, etc. The name literally means "limping", "stumbling", or "slumping", and has been borrowed by Western ethnomusicologists to refer generally to irregular, or additive meters (Brăiloiu 1951; Fracile 2003, 198; Reinhard, Stokes, and Reinhard 2001, §II, 4).
In Turkish folk music, these metres occur mainly in vocal and instrumental dance music, though they are found also in some folksongs. Strictly speaking, in Turkish music theory the term refers only to the grouping of nine pulses into a pattern of 2+2+2+3 (Reinhard, Stokes, and Reinhard 2001, §II, 4). Some examples are shown below.:
|5||2+3||türk aksağı [Bulg: Paidushko]|
|7||2+2+3||devr-i turan [Bulg. Račenica]|
|3+2+2||devr-i hindi (Bektaş 2005, 6–7) Bulg. Lesnoto), Četvorno|
|9||2+2+2+3||aksak [Bulg. Daychovo]|
|13||2+2+2+2+2+3||[Bulg. Elenino horo]|
|2+2+2+3+2+2||[Bulg. Krivo Sadovsko horo]|
|18||3+2+2 + 2+2+3+2+2||[Bulg. Jove male mome]|
|25||3+2+2 + 3+2+2 + 2+2+3 + 2+2||[Bulg. Sedi donka]|
The Belgian experimental rock group Aksak Maboul takes their name from this rhythm.
- Bektaş, Tolga. 2005. "Relationships between Prosodic and Musical Meters in the Beste Form of Classical TurkishMusic". Asian Music 36, no. 1 (Winter–Spring): 1-26.
- Brăiloiu, Constantin. 1951. "Le rythme Aksak" Revue de Musicologie 33, nos. 99 and 100 (December): 71–108.
- Fracile, Nice. 2003. "The 'Aksak' Rhythm, a Distinctive Feature of the Balkan Folklore". Studia Musicologica Academiae Scientiarum Hungaricae 44, nos. 1 and 2:197–210.
- Reinhard, Kurt, Martin Stokes, and Ursula Reinhard. 2001. "Turkey". The New Grove Dictionary of Music and Musicians, second edition, edited by Stanley Sadie and John Tyrrell. London: Macmillan Publishers.
- User. 2015. “The Music of Dave Brubeck”. Jazz Academy website (accessed 16 September 2016).
- Arom, Simha. 2004. "L'aksak: Principes et typologie". Cahiers de Musiques Traditionnelles 17 (Formes musicales): 11–48.
- Cler, Jérôme. 1994. "Pour une théorie de l'aksak". Revue de Musicologie 80, no. 2:181–210.
- Tanrikorur, Cinugen. 1990. "Concordance of Prosodic and Musical Meters in Turkish Classical Music". Turkish Music Quarterly 3, no. 1: 1–7.