ABSTRACT
There are twelve modal systems in the traditional Persian music system. The twelve modes or dastgāh comprising the radif constitute the complete collection of modes as passed down by masters according to their sources. The dastgāh are composed of many melodic segments of various lengths which are called gushe. The radif of twelve modes consists of some five hundred gushe in five main modal scales. The gushe can be from less than a half minute to several minutes long and are either free-rhythm, semi-metered or in 3/4, 6/8, 4/4 or, very rarely, 7/8. A free-rhythm gushe is called Āvāz or has many diverse names which designate certain melodic segments of various structures. The metered gushe can be termed chahār mezrab meaning “four beat” which generally defines the four unequal beats of a 6/8 meter counted ––. (long long short short). Other terms for a metered gushe are zarbi (rhythmic), do zarbi (two beat) do mezrab (two beat), reng (metered finale designed as a dance) and tasnif (medium or slow sung melody with meter). Another type of metered gushe is called kereshme (flirtation) characterized by the pattern .-.-.-- (short long, short-long, short short long long). Kereshme starts with metered pattern then can resolve in free-rhythm.
