The playing of one avartan of a tal on the table (pair of drums ) is called theka. It includes the repetition of sound syllabes (bol) to form rhythmic phrases. There are different types thekas, for example jhaptal and sooltal have both ten matras but their thekas differ. In jhaptal, there are three hand claps and one blank, in sooltal there three claps and two blank, thus making ten as mentioned in the following Table:
Beats 1 2 3 4 5 6 7 8 9 10
Sooltal 1 2 3 4 5 6 7 8 9 10
The word "theka" literally means "support" (Pathak 1976). Originally the theka was nothing more than a "groove" that is laid down for the accompaniment of other musicians. However in the last few centuries it has emerged as "the" signature for any north Indian tal.
Theka is generally conceived of as a conventionally accepted arrangement of common bols. Such bols as Dha, Dhin, Ta, Na, and Tin are the most common. The majority of common thekas may be played using only these bols.
A very common example is tintal
XDha Dhin Dhin Dha 2Dha Dhin Dhin Dha 0Dha Tin Tin Na 3Na Dhin Dhin Dha
The topic of the theka and its bols is complicated by the pakhawaj. There are many thekas which are derived from this instrument. These tend to use very different bols. It is very common to see phrases such as Dha Dha Din Ta, or Te Te Ka Ta Ga Di Ge Na. One very common theka from the pakhawaj is Chautal; it goes like this:
XDha Dha Din Ta 2KiTa Dha Din Ta 3TeTe KaTa 4GaDi GeNa
We may make a few observations about the structure of theka. There is a tendency for theka to be based upo
XDhin Na 2Dhin Dhin Na 0Tin Na 3Dhin Dhin Na
In this example the structure Dhin Na Dhin Dhin Na is opposed by Tin Na Dhin Dhin Na
This symmetry is also illustrated in dadra tal; it goes like this:
XDha Dhin Na 0Dha Tin Na
In this last example the phrase Dha Dhin Na is reflected in the structure Dha Tin Na.
It must be stressed that there are numerous thekas which do not exhibit this symmetrical quality. Therefore symmetry must be considered a tendency rather than a rule. Rupak is a very common theka which is asymmetrical; it goes like this:
0Tin Tin Na 1Dhin Na 2Dhin Na
There is another observation that we can make about the structure of the theka; there is a tendency for the bols to follow the structure of the vibhag. If we look back at the jhaptal in the earlier example we see that the 2,3,2,3, clapping arrangement of jhaptal is reflected in the bols Dhin Na Dhin Dhin Na Tin Na Dhin Dhin Na. Again, the numerous exceptions show that this is merely a tendency rather than a rule.
Closly allied with the concept of theka is the prakar. The term prakar indicates that there is not just one way to play the theka but there are numerous variatons. Some of these variations are a technical necessity and others are artistic.