Vibro-acoustic modeling, numerical and experimental study of the resonator and its contribution to the timbre of Sarasvati veena, a South Indian stringed instrument

This paper is part of a special issue on Modelling of Musical Instruments. The Sarasvati veena is a South Indian plucked string wooden lute, whose unique timbre is characterized by the presence of nearly all harmonics, in the range from 0 to 2800 Hz, the augmentation of the second and third harmonic and the revival of higher harmonics with time. This can be attributed to the shape of its extended bridge and its wooden resonator. In this work, the vibrational modes of the resonator are studied and the corresponding frequencies related to the musical tones generated while playing the veena. Numerical modal analysis is performed by the finite element method on a computer-aided design model of the resonator top plate as well as the air cavity within the dome-shaped structure. The results are compared to the experiment for validation. The resonator modes provide support to the harmonics of the string vibrations and give rise to the typical timbre of the instrument. We also find that other mode frequencies of the resonator support microtones that are used in Indian raga music. This gives scientific basis to the role of the timbre of the veena in supporting the development and sustenance of South Indian classical music.