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
mesk 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.