Talas - rhythm patterns

Almost all music is played to some form of repetitive rhythmic beat. In western music there are different ways to describe these patterns (time signatures - 4/4, 3/4 etc). In carnatic, a rhythmic pattern is called thalam (aka tala).

The fundamental unit of time is called akshara kala (aka aksharam). All forms of tala are some fixed number of aksharas. There are 6 distinct groups (tala anga) of aksharas and these groups are combined to form talas. There are 7 talas and each is described as a combination of tala angas.

Tala Angas

There are 6 angas and for the first three, there is a prescribed way for vocalists to keep track of the beats using the palm and fingers of the right hand. The names of the angas and the way to track them is as described below.

Their names are:

anudhrutham - one beat with a duration of one aksharam.  Action: Down beat of the hand, palm facing down

dhrutham - two aksharas. Action: Two down beats of the hand. First palm down, then palm facing up.

laghu - This is an interesting anga that has variable number of beats. For now it is 4 aksharas. Action: First beat with hand (palm down), followed by three finger counts (little, ring, and middle - in that order)

guru - eight aksharas

plutham - 12 aksharas

kaka padham - 16 aksharas

Jathi

The laghu alone has variable number of aksharas. These variants are called jathi and there are 5 of them.

1. thisra jathi laghu - three aksharas
2. chathurasra jathi laghu - four aksharas
3. khanda jathi laghu - five aksharas
4. misra jathi laghu - seven aksharas
5. sankeerna jathi laghu - nine aksharas

Usually just plain laghu with no qualifiers refers to chathurasra jathi laugh.

Tala

There are 7 talas in carnatic music and each of them is a combination of a few angas. To describe  them concisely I have used the following abbreviations

A = anudhrutham, D = dhrutam, L = laghu

1. dhruva talam - Consists of the following four angas : L D L L
2. matya talam - L D L
3. rupaka talam - D L 
4. jhampa talam - L A D
5. thriputa talam - L D D
6. ata talam - L L D D
7. eka talam - L

In any composition the talam will be stated as something like "chathurasra jathi rupaka talam". So how many aksharas in that cycle?

The basic talam is rupaka which has one dhrutham (D) and one laghu (L). The laghu variant is chathurasra jathi which means it has four aksharas. So this talam  (D L) has 2 + 4 = 6 aksharas.

Though multiple combinations of jathi and talam are possible not all are widely used. Some common talams are

• chaturasra jathi triputa talam (aka Adi thalam)
• chaturasra jathi rupaka talam
• thisra jathi thriputa talam
• khanda jathi ata talam