Causal Analysis of Carnatic Music: A Preliminary Study

TL;DR

This paper introduces a novel causal analysis framework for Carnatic music using compression-based measures, revealing structural relationships between complex compositions and derived ragas, with implications for musicology.

Contribution

It presents the first causal discovery method applied to Carnatic music, utilizing surrogate data and compression complexity to uncover structural causes in compositions.

Findings

Complex compositions influence the structure of derived ragas.

Structural causes are identified between Meḷakarta and Janya ragas.

Analysis of special Janya ragas provides insights into their origins.

Abstract

The musicological analysis of Carnatic music is challenging, owing to its rich structure and complexity. Automated \textit{r\=aga} classification, pitch detection, tonal analysis, modelling and information retrieval of this form of southern Indian classical music have, however, made significant progress in recent times. A causal analysis to investigate the musicological structure of Carnatic compositions and the identification of the relationships embedded in them have never been previously attempted. In this study, we propose a novel framework for causal discovery, using a compression-complexity measure. Owing to the limited number of compositions available, however, we generated surrogates to further facilitate the analysis of the prevailing causal relationships. Our analysis indicates that the context-free grammar, inferred from more complex compositions, such as the \textit{M\=e\d{l}akarta} \textit{r\=aga}, are a \textit{structural cause} for the \textit{Janya} \textit{r\=aga}. We also analyse certain special cases of the \textit{Janya r\=aga} in order to understand their origins and structure better.