In Ottoman / Turkish music theory, the term usul denotes a rhythmic pattern that forms the framework of a composition. An usul can be as short as 2 beats or as long as 120 beats. The term usul has often been translated as "meter", but usul and meter are not exactly the same thing. Both of them are defined by a (repeating) rhythmic pattern that with a more or less complex inner structure of beats of differentiated duration and weight. However, in contrast to meters, the definition of an usul always includes a performable rhythmic pattern that can be played on drums or just by striking ones knees with the hands. This pattern has a standard pronounceable code-text built from combinations of the syllables dum, du-um, tek, tekkyaa, teke, te-ek, where dum, du-um 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. Another difference of usul to meter is that whereas short usuls are almost identical to western types of meters (2/4, 3/4, 4/4, 6/4 etc) in their function, the longer types of usuls (28/4, 32/4, 120/4) are compound metric structures that underly longer sections of entire compositions, and are thus rhythmic frameworks rather than meters.

Usul is the rhythmic counterpart to maqam. The parallel notion to usul in Indian music is tala. In music, a maqam [sic] (plural maqamat) is a technique of improvisation that defines the pitches, patterns, and development of a piece of music. ... The term Tala can refer to: A rhythmic pattern in Carnatic or Hindustani (where it is also spelled taal or tal) music. ...