A cepstrum based approach for identifying tonic pitch in Indian classical music

This work addresses the task of tonic pitch identification in Indian classical music. The drone or the tambura establishes the tonic in Indian classical music. A cepstrum based pitch extraction technique is proposed to identify the tuning of the tambura. We show that by identifying the musical note Sadja in the lower octave of a performance, the pitch of the tonic can be identified accurately. We also show that by estimating pitch of low energy frames, tonic can be identified with greater speed and higher accuracy. In order to further enhance the speed and also illustrate the ubiquitous nature of the tonic, a Non-Negative Matrix Factorization (NMF) technique based method is developed to identify tonic. The proposed methods are validated by testing on a large varied dataset and accuracies close to 100% is reported.