Short answers, pulled from the story.
Syama Sastri was a composer and musician of Carnatic music, born on the 26th of April 1762 in Tiruvarur, Tamil Nadu. He is recognized as the oldest of the Trinity of Carnatic music, the other two members being Tyagaraja and Muthuswami Dikshitar.
The Ratnatrayam, meaning Three Jewels, refers to Syama Sastri's three celebrated svarajatis: Kamakhsi Anudinamu in raga Bhairavi, Kamakhsi Padayugame in raga Yadukula kambhoji, and Rave himagiri kumari in raga Todi. They are intended for concert performance rather than dance.
Syama Sastri is said to have composed about three hundred pieces in all, fewer than his two contemporaries Tyagaraja and Muthuswami Dikshitar. His output includes kritis, varṇas, and svarajatis, most of them addressed to the Goddess Kamakshi.
Syama Sastri used the mudra, or musical signature, Syama Krishna. This name appears in his kritis, varṇas, and svarajatis as a composer's mark. He is also known by his birth name Venkata Subrahmanya Iyer.
Syama Sastri first learned music from his maternal uncle, then received formal training from Adiappayya, a durbar musician at Thanjavur. His notable disciples include Alasur Krishna Iyer, Porambur Krishna Iyer, Tarangambadi Panchanada Iyer, and Dasari; his son Subbaraya Sastri was also a composer.
Syama Sastri's compositions use a formal register of Telugu that borrows heavily from Sanskrit, making them more accessible to the learned than to general audiences. He was also known for composing in complex tāḷas. Limited access to the printing press and a small number of disciples further restricted how widely his works were transmitted during and after his lifetime.