in Hindustani music (q.v.), a musical form based on a Hindi song in two parts that recur between expanding cycles of melodic and rhythmic improvisation. In a standard performance a slow (vilambit) kayal is followed by a shorter, fast (drut) kayal in the same raga.

The kayal is related to the longer melodic form known as the dhrupad but has fewer restrictions. It is usually accompanied by tabla (drums) and tamboura (lutes) in a variety of talas (metric cycles). Kayal is ordinarily performed by a vocalist. The rhythm of the melodic performance is nonmetric, but the percussion accompaniment is cast in a tala, and the time cycle is shaped by the repeated pattern (theka) performed by the accompanist.