Which South Indian poet and composer has a school of music where Sooryakantam  is called Chāyāvati ?
Suryakantam Suryakantam or Sooryakantam (pronounced sūryakāntam) is a rāgam in Carnatic music (musical scale of South Indian classical music). It is the 17th "melakarta" rāgam (parent scale) in the 72 "melakarta" rāgam system of Carnatic music. It is called Chāyāvati in Muthuswami Dikshitar school of Carnatic music.
Pandanallur style Meenakshisundaram Pillai, whose ancestors were nattuvanars, was a descendant from the Thanjavur Quartet, which comprised four brothers: Chinnaiah, Ponniah, Sivanandam and Vadivel. The works of these four brothers, who were court composers in the early 19th century in Thanjavur, form the main classical masterpieces of Bharata Natyam.