Spectral analysis and investigations of audio signals using signal processing tools - A case study on notes in carnatic classical music to analyse the overtones and harmonics

Tones have a fixed frequency while notes in music are a combination of tones or frequencies which are observable in the power spectra. The frequencies present in the spectra are characteristic of the pitch, timbre, amplitude of the input audio signal. These features are illustrated in a case study on Carnatic music system by studying the frequency spectra of input signals from veena and vocal. It is found that the spectra contain other harmonics and overtones along with input signal frequency due to resonance effects and the characteristic overtones can be analyzed to get useful information about the timbre of the source. In particular spectra of notes S, R1, R2, M1, P, D2 from vocal at G# and Veena at E are analysed.