Wikipedia
Swaramelakalanidhi is a much celebrated musicological treatise of 16th century Vijayanagara. Authored by Ramamatya in the year 1550, the work is counted among the sangita shastra navaratnas or the nine 'gems' of the theory of Karnataka Music. The work's importance lies in the fact that it is more relevant and related to modern practice than the books written prior to it. Spread over five chapters, it deals primarily with the theory of raga, describes the melas for the classification of raga -and the different shuddha svaras and vikrta svaras constituting the melas.
Works by other celebrated contemporaries like Pundarika Vitthala and Somanantha also deal with similar themes, namely the description of ragas, their classification under melas and the enumeration of the shuddha and vikrta svaras constituting the melas. Minor ideological difference can however be discerned among these works.