What symmetry is to the plastic arts, rhythm is to music.
A raga is totally dependent on tal (pronounced taal). Vocal music, instrumental music and dance rely on rhythm for its effect on the audience. Tal/tala  is the means of measurement of time in music or dance. Rhythm is the breaking up of time in small units. Time is cut into pieces at certain regular intervals. Literally tal means the palm of the hand; the time is measured by the clapping of hands (tali) or beats of drums or sticks. Tal is divided into two halves; Bhari (full) starting with sam, and khali (empty) starting with khali. So tal is an organisation of rhythms or different beats in certain groupings which are smaller units of matras. These rhythmic units repeat themselves in cycles. The drummer has to produce the spoken syllable indicating the position of the hand on the drum. The permutation related to tal are as follows: