The Trinity - Thyagaraja, Dikshitar, Syama Shastri
Maratha kings (1674-1947) who succeeded Nayakas at Tanjavur continued the patronage of music and arts and Tanjavur became one of the great centers for music. It was during this Tanjore Maratha period that the famous Carnatic Trinity revolutionized Carnatic music.
The trinity of Thyagaraja(1767-1847), Muthuswami Dikshitar(1776-1835) and Syama Shastri (1762-1827) were contemporary composers. They were never directly patronized by any royal court but were attached to temples of Vaishnava cult. Muthuswami Dikshitar composed most of his krithis in Sanskrit, while the others worked in Telugu. They were probably of Telugu origin or could have composed in Telugu because it was the prevalent language for literature at the time.
The main contribution of the trinity was the standardization of kriti format as the most important form of Carnatic music. Starting in the 16th century, composers like Muthu Tandavar and Margadarsi Sesha Ayyangar had experimented with the kriti format and the characteristic pallavi-anupallavi-charana structure, one that was followed in Kshetragna's padas. The trinity, particularly, Tyagaraja perfected this format with the result that it dominates Carnatic music today. Thus, unlike Purandaradasa and musicians of his generation, who had perhaps a couple of dozen ragas to work with, Tyagaraja experimented with hundreds thanks to the Melakartha scheme. The 700 odd known krithis of Tyagaraja feature 212 ragas; 121 of these ragas have only one composition in them. Like the Haridasas (Purandara et al), disciples of Trinity carried forward the great musical tradition and popularized their compositions. This was also the time, music came to be associated more with the temples than the courts. It took a very religious and pious color, making it highly acceptable in larger society (unlike in North India).
By 1850 AD the evolution of Carnatic music system was complete. PurandaraDasa had given the teaching system and krithis with the background of philosophy and Bhakthi. The Raaga classification and system was perfected with Venkatamakhi's Melakartha system. The trinity had given a great number of krithis in a large number of Raagas.