I just stumbled upon this version of Mamava Pattabhi Rama on Youtube. The artist says in the description that it is a genuine attempt to interpret the notation for the Kriti provided in the Sangeetha Sampradaya Pradarshini.
Also, he says:
This is purely a Baroque version and a comparison with the present version definitely impedes the listening pleasure.
Listening to this version by closing your eyes and erasing your memories about the present version of this song will give you a delectable experience.
Here is the link:
https://www.youtube.com/watch?v=YpxbH2FeyQ0
While it is indeed fascinating to listen to the composition by not comparing it with its current day version, I wonder if Sri. Muthuswamy Dishithar really sang it so plainly. Accustomed as we are with the modern method of singing, it is really difficult to imagine somebody like Dikshithar singing it like this. Because then, it would mean that other kritis like Balagopala would have been sung similarly, which is way different than we hear them now. But I just can't come to terms with the lack (or lightness, if you will) of gamakas in this way of singing.
That is a fascinating channel, aptly named "The Lost Melodies". This was just an example. There are many other renderings there from the SSP as well as Walajpet versions of Thyagaraja kritis, besides compositions from other schools.
The description of the channel reads:
The single aim of this channel is to resurrect the lost versions which do justice to the raga lakshanam as prescribed in the early treatises and to the real spirit of our composers.
This is an attempt to reconstruct the versions that remain only in the manuscripts or in texts.
All these versions will be alien when heard for the first time. Repeated learning and the understanding that we are travelling back gives us a listening pleasure.
Kudos to the creator Sri. Aravind T Rangarajan for what's obviously well researched and painstaking work.