The rhythmic modes of Turkish music are known as usûller (singular usûl). A composition will generally have a particular usûl asscoiated with it, and on a piece of Turkish sheet music this is indicated (together with the makam) below the title. An usûl consists of regularly repeating sequence of beats, with each beat represented by one of two different types of drumstroke: the 'dum' stroke is produced at the centre of the drum and the 'tek' stroke at its edge. The time signature at the beginning of the pattern consists of two numbers: the bottom number indicates the relative length of each beat and the top number indicates how many of these beats make up the repeating unit of the pattern. Some of the more common usûller are listed below, together with some of the rhythmic patterns associated with them.
Şarki Devr-i Revani