Improving Melodic Similarity in Indian Art Music Using Culture-Specific Melodic Characteristics

Detecting the occurrences of rāgs’ characteristic melodic phrases from polyphonic audio recordings is a fundamental task for the analysis and retrieval of Indian art music. We propose an abstraction process and a complexity weighting scheme which improve melodic similarity by exploiting specific melodic characteristics in this music. In addition, we propose a tetrachord normalization to handle transposed phrase occurrences. The melodic abstraction is based on the partial transcription of the steady regions in the melody, followed by a duration truncation step. The proposed complexity weighting accounts for the differences in the melodic complexities of the phrases, a crucial aspect known to distinguish phrases in Carnatic music. For evaluation we use over 5 hours of audio data comprising 625 annotated melodic phrases belonging to 10 different phrase categories. Results show that the proposed melodic abstraction and complexity weighting schemes significantly improve the phrase detection accuracy, and that tetrachord normalization is a successful strategy for dealing with transposed phrase occurrences in Carnatic music. In the future, it would be worthwhile to explore the applicability of the proposed approach to other melody dominant music traditions such as Flamenco, Beijing opera and Turkish Makam music.