Tanpura (or tambura) is an unfretted long-necked lute, with four strings, used
exclusively for providing the drone in Indian classical music. The purpose of drone
is to establish a firm harmonic basis for a musical performance by constantly
playing a particular note or a set of notes. The strings in tanpura are tuned generally
to Sa, and Sa’ and Pa or Ma depending on the raga of the music. In normal practice,
female singers use smaller tanpuras. Generally, its sound appears to be a little rough
indicating strong presence of jitter, shimmer, and complexity perturbations. It is
played with an unvarying tempo and tuned to only three fixed notes two of them
being the first note of an octave. The existence of excellent consonance between the
notes used in ragas in Indian music and the tanpura sound seems to be the basis for
musicians to choose tanpura as the drone instrument. It is mandatory to use it to
practice singing of vocal music which helps in purifying the ability to produce
correct ‘shrutis’ (micro-tonal note positions) by feeling the consonance between the
singing and the tanpura sound.
The sound of a well-tuned tanpura, and hence the resulting drone, is remarkably
rich in overtones and creates a pleasant “melodic background” for the performance.
The tanpura drone is widely recognized for enhancing the musicality of the raga
being played by constantly reinstating the notes which form the essence of the raga.
The distinctiveness of tanpura’s sound is due to the unique manner in which the
strings interact with the soundboard.
Among mechanically induced sound effects naturally afforded by musical
instruments, the generation of overtones in tanpura drones playing is one of the
more spectacular and intriguing examples. In Indian musical tradition, the phenomenon is known as jawari (meaning ‘life-giving’) and arises from the impact of interaction of the vibrating string with a hard-surfaced bridge. As a vibrational phenomenon, the jawari effect has attracted scientific interest for almost a century,
starting with the musical acoustics poineering work by Sir C. V. Raman.