He is another musician I have not had an opportunity to listen in person and added to that is the fact that I was quite unaware of him and his music for what i can say were my early listening time. Obviosuly it was my shortcoming and perhaps lack of initiative in looking for high quality musicians in those days.
It was indeed a rude surprise that I got to know of him and his music from my aunt Late Savitri Satyamurthy (violin) who used to accompany him in a lot of concerts. She not only got me hooked into his music but also helped me in getting hold of a copy of his Music Academy concert of 1985 !! One of the recordings below has my aunt accompanying in a radio concert 🙂
All I can say is that I enjoy his music tremendously and his unique approach in employing gamakams from minimal to the so called normal levels brings out a beauty that are beyond my ability to explain. One composition that left an indelible mark is ‘vEl edutta kaiyyE ‘ in toDi – not a very often heard composition.
Shankar Krish's Blog 
In the very first concert of Dr S Ramanathan that you have uploaded (T N Krishnan & U K Sivaraman – 1984), the second krithi is Vinatha Sutha Rara in Huseni by Saint Thyagaraja (not Jayanthasena as you have noted). The Jayanthasena krithi is Vinatha Suthavahana.
It is the third krithi, not the second as noted by me.