Ramamatya's Swaramela-Kalanidhi (1550 AD)
But it is said that the various musicians who came and settled in Vijaynagar Empire had their own ideas of how music should be sung. The mutual contradictions were so great that Vijayanagar King Achutharaya commissioned Ramaamaatya around 1550 to write a treatise reconciling the contradictions. Ramamatya wrote the Swaramela Kalanidhi. It has 5 chapters - Preface, Swaraprakarana, Veenaprakarana, Melaprakarana and Ragaprakarana. It puts in proper perspective the importance of theory as well as practice in music and assigns a proper placing for both. He explains 19 Melas and 166 Janya Raagas. He, thus, laid the foundations for the present theoretical framework. This was later expanded by Venkatamakhin into 72 Melas in his Chaturdandi Prakasika.
He has also discussed several musical instruments. The seven-stringed veena with four playing strings and three tala or rhythm strings emerged into prominence with Ramamatya who has discussed Sarwaraga mela veena. It is also said that Ramamatya constructed the modern Vina and evolved the technique of Vina playing involving both plectral technique as well as a manipulation of the strings by the fingers of the left hand