Tala is a rhythmic cycle made up of a number of beats. In the Carnatic or South Indian rhythmic system the shortest cycle is made up of 3 beats whereas the longest cycle has 29 beats.
There are 3 basic units which combine to form a Tala cycle:
1. Laghu (denoted by I) is a clap of the hand followed by counting of the fingers; these counts could vary from 3 to 4 to 5 to 7 to 9, based on the jatis, i.e. 3=tishra, 4=chatusra, 5=khanda, 7=mishra, 9=sankirna.
2. Drutam (denoted by O) is a clap of the hand followed by a wave of the hand; it is a fixed unit of two beats.
3. Anudrutam (denoted by U) is simply a clap of the hand; it is a fixed unit of one beat.
The modern South Indian Tala System is made up of 7 parent Talas: Dhruva, Matya, Rupaka, Jhampa, Triputa, Ata, Eka. These in turn have 5 variations, each based upon the Laghu variables, i.e. 3 or Tishra, 4 or Chatusra, 5 or Khanda, 7 or Mishra and 9 or Sankirna. Thus 7 Parent Talas x 5 Jatis = 35 Talas. (Refer to Tala chart below)
Each Tala has a formula made up of symbols which denote Laghu, Drutam and Anudrutam. As mentioned before, Laghu=I, Drutam=O, and Anudrutam=U. As derived from the chart, most Talas are combinations of Laghu and Drutam; but Jhampa Tala combines Laghu, Drutam and Anudrutam; wheras Eka Tala is made up of just Laghu.
Nadai is a term which means subdivision of beats. Based on the Jatis, each beat could thus be subdivided into Tishra (3), Chatusra (4), Khanda (5), Mishra (7) and Sankirna (9). So theoretically 35 Talas x 5 Nadis permutate into 175 possible time cycles! (See e.g. on the Tala Chart page)
Chappu Talas: these 3 Talas do not belong to the 35 Talas described above. They are also counted differently, using short and long beats, i.e. groups of 2s and 3s. For e.g. Khanda Chappu Tala is made up of 5 beats subdivided into 2+3. Mishra Chappu Tala is a 7 beat cycle, usually counted 3+2+2, and Sankirna Chappu Tala is a cycle of 9 beats counted 2+2+2+3.
Korvai (also known as Muktayam), is a rhythmic composition based on any given Tala, and its length may cover one or more cycles of the chosen Tala. Korvais are usually repeated three times and resolve on the first beat of the following cycle.
Mastering the South Indian art of drumming involves not just developing technique and a good sense of time, but also a quick brain for rapid mathematic calculations! With all these tools at hand, a virtuoso percussionist from this genre of drumming can create incredible grooves as well as intricate solos in all possible time cycles.