One cycle of the matras of a tal is called avartan. For example, dadra has six matras; as soon as six matras are completed, we have done one avartan (cycle) of dadra tal.

The avartan is the cycle in North Indian Music. It is composed of measures (vibhag) which are in turn composed of beats (matra).

The avartan is in some ways comparable to the Western cycle (e.g. a 16 bar blues pattern) with but a few differences. One of the biggest differences is that in Western music the measure is considered inviolate, while in North Indian music the cycle is considered inviolate. That is to say that a Western musician would think nothing of establishing a 16 bar pattern, break the pattern for some artistic reason and then reestablish it; however the measures would all be the same. Conversely, Indian musicians typically will mix the measures. For instance jhaptal is four measures of two-beats, three-beats, two-beats, three-beats respectively, however the overall 10 beat pattern may not be altered.

Avartans may be of any number of beats. The most common numbers are 16, 14, 12, 10, 8, 7, and 6. Most of the music played in Northern India today is in one of these numbers.

by David Courtney, Ph.D