The first round of thaniavarthanam looks like net practice - warming up for a big one. After playing 4 syallables in chatursram, mani sir takes 24 (12 in fast tempo) mathrai syllable for a small korvai. You cant call this as a korvai, we can call this as abhiprayam. I have seen many people calling this as a korvai and many people calling this as Abhiprayam (Abhiprayam differs ;-)).
Though the abhiprayam looks simple its a bit confusing. The abhiprayam is constructed in the following way. First lets see the structure and then the abhiprayam as syllables.
Part 1 :
Step 1 : First syllable for 3 Aksharams - 12 Matharis ( splitted as 8 and 4 )
Step 2 : Second Syllable for 2.5 Aksharams - 10 Mathrais ( splitted as 7 and 3 )
Step 3 : Third Syllable for 1.5 Aksharams – 6 Mathrais.
Total comes to 28 Mathrais or 7 Aksharams. (Since its chatursram, a beat consists of 4 mathrais, it comes to 7 Aksharams)
A balance of 36 matharis or 9 aksharams is pending. Now this 9 is divided into 3 parts. A 3 akshram syllable is taken as arithi which constitutes this Abhiprayam.
Harishankar started of few fast phased syllables and played a simple abhiprayam for 3 Avarthanams. The structure of the Abhiprayam is very simple, but a simple change made it sounds better.
The strucutre needs no diagrams a its a straigh forward abhiprayam, if you dont understand I will give more details on this.
6 3 , 6 3, 6 3 - 27
8 3 , 8 3 ,8 3 - 33
10 3, 10 3, 10 - 36
the total comes to 96. which comes for 3 Avarthanams. Six can be played as Thatheekitathom, 8 as thaka Thatheekitathom and 10 as thakathina Thatheekitathom.