Varsha-ji: Thanks for setting this up. Semmu and others, please feel free to step in.
Let us begin with two examples for accompaniment.
1) The first is KVN-MC with the legendary UKS and the piece I have chosen in Telisi rama in poornachandrika in Adi Talam. In some sense, in this simplest of pieces these three great vidwans have given us the entire universe of carnatic music in a capsule.
I would like for us to first notice how UKS marks the kalapramanam with clear and crisp strokes, right at the outset. From the second sangati of the pallavi, he sets up the cadence of the piece. With each sangati he adds embellishments and he finally adds a compatible sollu along with "ri sa ni pa ma ga ma ri sa". You will see how this inspires KVN soon.
Then watch how carefully he keeps time with just a simple chapu (his trademark) instead of a tirmanam before they launch into the anupallavi. And to keep the gait of the piece going UKS alternates between highlighting the elements of the sahityam that fall on the beat of the talam, while also using a generous amount of gumki along with the "dhim ta dhimita ta dhim" to provide the perfect rounding. This is especially important in Tyagaraja's compositions where the syllables fall so perfectly on the beat, to the extent that you don't even have to keep talam with your hands!
Now note the perfect pause before "nijatatva". As he enter the charanam, "rAmAyaNa capalakSula pEru" UKS launches into continuous phrases and attempts a simple nadai variation that adds so much zest to the proceedings.
KVN as though inspired by UKS's accompaniment for the last sangathi, launches into his first kalpanaswaram as "ri sa ni pa ma ga ma ri sa" - Telisi rama! Just 2-3 short round of swarams. I will let you enjoy the rest without my running commentary
Such understated elegance. Beautiful nadham. The gentle accompaniment lifts the piece to great heights. And to top it all off, KVN-UKS make it appear so easy.
2) This is TVS with Trichy Sankaran. A relatively rare combination. Despite being contemporaries, it is not often that you see these two come together. The piece I have chosen is an MMI classic: Sri Mathrubootham.
This misra chapu nadai amaippu is a Pazhani school classic. For the first few sangatis, you will find that TS does not come into the standard misra chapu gait of "dhim tha tha dhim, taka dhim tha tha dhim"; almost leaving the audience longing for it. And when he does, it is absolute magic!
By this time, TVS is exploring the beauty of the anupallavi: sOma sakhaM nata Suka sanakaM. At this time TS is providing very solid reinforcement with the classic misrachapu pattern. But when TVS starts sOmaM SirO-dhRta sUrya gangaM, listen to how Sankaran launches into his trademark continuous play. Such a gift he has, to be able to produce that pattern on demand with providing variation at high speeds too without what we refer to as "thesal". But note that, he pauses at just the right time to embellish "guruguha" taranga lingam with straight strokes. Imagine the level of knowledge of the composition these mridangists have! The short tirmanam of: dhim takita dhim played three times stops in time for the grand opening of the charanam.
The charanam is a in typical Dikshitar fashion, fairly complex with multiple rhythmic variations. TS sings along till dAsa jana santOsha karaNam. And then the madhyama kalam begins. How beautifully he anticipates the beat and the metric structure and plays perfect on the syllables of sadasivam paramasivam. And then he know that TVS is coming back to do the sangati again. He uses the gumki to great effect, while he waits for the return. Then he pounces.
The swarams follow this. This is such classic MMI, with superb variations on gmpgmrs, with the ri going dheergam on occasion. Sankaran's anticipation is superb on every element of this.
Now, it would be great if you can spare 11 minutes and listen to both the pieces again. But this time close your eyes!
If there is sufficient interest we could now proceed with the following features in our curated listening.
Nadai amaippu, providing variations for sangatis, vallinam-mellinam embellishment and sensitivity to sahityam. And perhaps after this, we can start contrasting styles. Maybe after this we can discuss, how to play for varnams, neravals, rtps etc with suitable examples.
That said, I will pause now, so we can have some discussion of these pieces. I am sure others, esp Semmu will have valuable opinions on this.