Hand gestures in classical carnatic Indian music is an important part and it is performed both by the singers and listeners. Here are few rules about hand gestures.
Kriyas of a tala are the expression of time durations on the hand and determine angas (those which take up the time measures). Marga kriyas are of two kinds, namely, sasabda and nishabda. Nishabda kriyas are silent expressions of the time duration by different movements of the hand. Of these, avapa is counting the time duration by folding the fingers of the hand turned upwards. Anudruta is a beat of the hand raised up to the distance of one-and-a-half fingers. Druta is represented by a beat and wave. The number of the finger counts varies according to the aksharakala in jatis (species) of the laghu.
One of the popular talas is Aditala. Kriyas (actions) of the Aditala of the Carnatic system consist of a beat followed by the counting of three fingers from the little up to the middle finger (laghu) and a beat and a wave of the hand and again a beat and a wave of the hand (two drutas), making a total of eight aksharas. Tanat tala of the Hindustani system resembles Aditala in respect of the number of aksharas, which are eight. It is counted differently, the beats fall on the first, third and seventh syllables. The expressions of tala are a continuous stream of avartas (rounds), each round reaching the fixed point of origin. In Tamil convention, a single avarta is known as orutalavartana. Each avartanai of Aditala has eight aksharas.