In Ottoman classical music, usul is an underlying rhythmic cycle that complements the melodic rhythm and sometimes helps shape the overall structure of a composition. An usul can be as short as two beats or as long as 128 beats. Usul is often translated as "meter", but usul and meter are not exactly the same. Both are repeating rhythmic patterns with more or less complex inner structures of beats of differing duration and weight. But a student learning Turkish music in the traditional meşk system first memorizes the usul kinetically by striking the knees with the hands. The student then sings the vocal or instrumental composition while performing the underlying usul. This pedagogical system helps the student memorize the composition while internalizing the underlying rhythmic structure.

Usul patterns have standard pronounceable vocables built from combinations of the syllables düm, dü-üm, tek, tekkyaa, teke, te-ek, where düm, dü-üm indicate a strong low beat of single or double duration, and tek, tekkya, teke, te-ek indicate various combinations of light beats of half, single or double duration. Long usuls (e.g., 28/4, 32/4, 120/4) are compound metric structures that underlie longer sections of entire compositions.

In Ottoman times, the usul was realized by drummers. Drums are generally omitted in modern performances except for Mevlevi. When performing music for the Mevlevi ceremony, drummers traditionally play embellished (velveleli) versions of the usuls.

Instrumental improvisations (taksim) and vocal improvisations (gazel, mersiye, etc.) are generally performed in "free" rhythm, with no usul.

The melodic counterpart to usul rhythmic mode is makam melodic mode. The parallel system to usul in Indian music is tala.

Turkish Usuls and Aksak Rhythms: A Comprehensive Guide ​

Introduction ​

Turkish music is renowned for its complex rhythmic structures, which form an integral part of both classical Ottoman music and Turkish folk traditions. Two key concepts in Turkish rhythm are Usul and Aksak.

Usul ​

Usul (plural: usuller) is the Turkish term for rhythmic cycle or meter. It's comparable to time signature in Western music, but often more complex. Usuller can range from simple patterns of a few beats to intricate cycles of over 100 beats. They provide the rhythmic foundation for Turkish classical and folk music.

Aksak ​

Aksak, meaning "limping" in Turkish, refers to asymmetrical rhythms that combine units of 2 and 3 beats. These rhythms are characteristic of Turkish and Balkan music, creating a distinctive "limping" or "uneven" feel. While all aksak rhythms are usuller, not all usuller are aksak.

Note on Rhythm Notation ​

In this guide, we notate the rhythms using 16th notes (e.g., 5/16, 7/16) rather than 8th notes. This choice reflects the traditionally fast tempo at which many of these usuls are performed. In classical Turkish music, these rhythms are often played at a pace where each notated beat (16th note) corresponds roughly to one pulse, typically ranging from 80 to 120 beats per minute for the 16th note, depending on the specific usul and the nature of the piece.

However, it's important to note that tempo can vary widely based on the style of music, the specific composition, and the performer's interpretation. Some slower pieces or more contemporary interpretations might take a more relaxed tempo.

In the following descriptions, we use "X" to represent the main strong beat (düm in Turkish percussion terminology), "x" for secondary beats (tek), and "." for silent beats.

Detailed Rhythm Descriptions ​

5/16 Türk Aksağı ​

• Pattern: X.x.. (2+3)
• Description: One of the most fundamental aksak rhythms. Its name literally means "Turkish limping."
• Usage: Widely used in Turkish folk music, especially in western Turkey and the Balkans. It's also found in classical compositions and forms the basis for more complex rhythms.
• Significance: Türk Aksağı is often considered the quintessential aksak rhythm, embodying the characteristic "limping" feel of Turkish music.

5/16 Hücum Semai ​

• Pattern: X..x. (3+2)
• Description: An alternative 5/16 pattern, often felt as a "reverse" of Türk Aksağı.
• Usage: Commonly used in the fast final section (hücum means "attack" in Turkish) of classical fasıl performances.
• Significance: Hücum Semai showcases how the same number of beats can create a distinctly different feel when arranged differently.

7/16 Devr-i Hindi ​

• Pattern: X...x.. (4+3)
• Description: The name means "Indian cycle," though its origins are uncertain.
• Usage: Found in both classical Ottoman music and folk traditions.
• Significance: Devr-i Hindi demonstrates how Turkish music incorporates longer beat groupings into aksak rhythms.

7/16 Devr-i Turan ​

• Pattern: X.x.x.. (2+2+3)
• Description: An alternative 7/16 pattern, providing a different rhythmic feel from Devr-i Hindi.
• Usage: Less common than Devr-i Hindi, but still present in the classical repertoire.
• Significance: Devr-i Turan shows how the same total number of beats can be subdivided differently, creating distinct rhythmic characters.

9/16 Aksak ​

• Pattern: X.x.x.x.. (2+2+2+3)
• Description: The quintessential "limping" rhythm of Turkish music.
• Usage: Extremely common in both folk and classical music throughout Turkey and the Balkans.
• Significance: Aksak is perhaps the most well-known Turkish rhythm internationally, epitomizing the aksak concept.

9/16 Evfer ​

• Pattern: X..x..x.. (3+3+3)
• Description: While not strictly an aksak rhythm, its 9/16 meter is significant in Turkish music.
• Usage: Found in classical Turkish music, often for more lyrical pieces.
• Significance: Evfer demonstrates how Turkish music uses complex meters even in symmetrical patterns.

9/16 Ağır Düyek ​

• Pattern: X....x... (5+4)
• Description: A slower, more elaborate version of the common 8/8 Düyek rhythm.
• Usage: Used in slower, more serious classical pieces.
• Significance: Ağır Düyek shows how Turkish music adapts and extends simpler rhythms to create more complex ones.

10/16 Aksak Semai ​

• Pattern: X.x.x.x.x. (2+2+2+2+2)
• Description: An extended aksak rhythm, building on the basic aksak pattern.
• Usage: Found in both classical and folk traditions, often for dance music.
• Significance: Aksak Semai demonstrates how aksak patterns can be extended to create longer, more complex rhythms.

11/16 Tek Vuruş ​

• Pattern: X.x.x.x.x.. (2+2+2+2+3)
• Description: A complex aksak rhythm. The name means "single strike," referring to the final long beat.
• Usage: Less common, but found in some classical compositions and regional folk music.
• Significance: Tek Vuruş showcases the flexibility of Turkish rhythm, extending the aksak principle to create highly complex patterns.

13/16 Nim Evsat ​

• Pattern: X.x.x.x.x.x.. (2+2+2+2+2+3)
• Description: A highly complex aksak rhythm. "Nim" means "half," as this is half of the 26/16 Evsat rhythm.
• Usage: Found in advanced classical compositions.
• Significance: Nim Evsat represents the upper end of complexity in commonly used Turkish rhythms, demonstrating the sophistication of Turkish rhythm theory.

15/16 Raksan ​

• Pattern: X.x.x.x..x.x.. (2+2+2+3+2+2+2)
• Description: A long aksak rhythm. The name means "dancing" in Persian.
• Usage: Used in some classical pieces and regional folk music.
• Significance: Raksan shows how very long aksak patterns can still maintain a danceable quality, crucial in Turkish music.

18/16 Türk Aksağı (compound) ​

• Pattern: X.x.x..X.x..x.x.. (2+2+3 + 2+3 + 2+2+2)
• Description: A compound version of the 5/16 Türk Aksağı.
• Usage: Found in some advanced classical compositions.
• Significance: This rhythm demonstrates how basic aksak patterns can be combined to create more complex, compound rhythms.

25/16 Kapalı Curcuna ​

• Pattern: X.x.x..X.x.x..X.x.x..X.x.. (2+2+3 + 2+2+3 + 2+2+3 + 2+3)
• Description: One of the longest aksak usuls. "Kapalı" means "closed" and "curcuna" is a type of lively rhythm.
• Usage: Rare, used in very advanced classical compositions.
• Significance: Kapalı Curcuna represents the pinnacle of rhythmic complexity in Turkish music, showcasing how multiple aksak patterns can be combined into a single, extended rhythm.

Conclusion ​

These rhythms demonstrate the rich complexity of Turkish music's approach to meter and rhythm. The aksak patterns, in particular, showcase the sophisticated interplay between long and short beats that gives Turkish music its distinctive character. From the basic 5/16 Türk Aksağı to the complex 25/16 Kapalı Curcuna, these rhythms form a unique rhythmic language that is integral to the expression and emotion of Turkish music.

The use of 16th note time signatures reflects the traditionally brisk pace of many usul performances in classical Turkish music. This rapid pulse contributes to the music's energetic and intricate character, allowing for subtle subdivisions and complex interplays between rhythm and melody.

Understanding these rhythms not only provides insight into Turkish music but also offers a gateway to appreciating the diverse and intricate rhythmic systems found in music traditions around the world. The speed and complexity of these rhythms challenge musicians to develop high levels of rhythmic precision and listeners to engage with music in new and exciting ways.