Taala and its structure

What is a Taalam ?
Taalam indicates the rythm or beats in Carnatic music.
Just as a raaga extolls the bhavam of the song, so does the taalam, which reveals the mood of the song. The word 'thalam' is said to be derived from the combination of the words Thandavam & Lasyam. Thandavam is the dance of Lord Siva and Lasyam is the dance of Goddess Parvathi.

There are three different types of hand gestures that are used -
1. Thattu- downward beat with the palm facing down
2. Veechu - downward beat with palm facing up
3. Counts with the fingers.

This system of talams forms the rythmic basis for Carnatic music. It is based on 7 core talas which uses only the first 3 of the 6 possible components of an Indian talam - Anudrutam, Drutam, Laghu, Guru, Plutam, and Kakapadam.

Each and every talam has a structure, that is governed by the rules pertaining to it.
For example, if we take the most common tala - Chatusra Jaathi Triputa Talam (Adi Talam), we can describe the process of the tala thus :
1 beat of the palm of the hand on the thigh, followed by counting three fingers, then beating the palm and turning it over, then beating the palm and turning it over If we count a number each for every beat, fingercount or turn of the palm - the number comes to eight. So the tala has eight units. The units are called Aksharams and the Adi talam has 8 aksharams.

LAGHU :
The first part of the tala which consists of the beating of the palm & counting is called Laghu. Here the number of units is 4 (Chatusram) and the laghu is Chatusra laghu. The Jaathi of the laghu determines the jaathi of the tala so the tala is Chatusrajaathi Adi Tala.

DRUTHAM:
The next process of beat and turning the palm is called Drutham. It is done twice, so the tala has 2 druthams. Thus Chatusra Jaathi Triputa Talam(Adi) has one Chatusra Laghu and two druthams. The symbol for laghu is 1 and the number written beneath it represents the jaathi and the symbol for drutham is 0 and hence, this thalam will be represented thus
1 4 0 0

Thus, from the above, we understand that a tala has laghu, drtham and these are called Angams (parts) of the tala. In some cases, there may be half of drutham, i.e., just the beat of the palm without turning it and is called Anudrutham.