तानपुरा
The tanpura is the most fundamental instrument in Indian classical music — not because of its complexity (it plays only a repeating four-note drone) but because of what it does: it creates the sonic world within which the raga exists. Every classical performance happens against the continuous sound of the tanpura. Remove it, and the music loses its harmonic foundation; the raga loses its ground.
The tanpura closely resembles the sitar in construction — a large gourd body, long neck, and a flat-topped head — but it has only four strings and no frets. The four strings are tuned to Pa-Sa-Sa-Sa in the standard Pancham tuning, or Ni-Sa-Sa-Sa for ragas that omit Pancham. The bridge has a small thread (jivari) inserted beneath each string, which creates a buzzing, rich overtone when the string vibrates against it. This buzzing is essential — without it, the drone would be too pure and would not create the resonant cloud of harmonics that the tanpura is meant to produce.
The tanpura is played by continuously plucking each of the four strings in sequence — Pa (or Ni), then three iterations of Sa — in a steady, unhurried cycle that continues throughout the entire performance. The player sits beside the lead musician and maintains the drone without interruption, from the opening note of the alaap to the final note of the performance. Advanced tanpura players adjust the jivari thread subtly during a performance to keep the overtone blend correct as the music changes register.
The tanpura developed in roughly its current form in the sixteenth and seventeenth centuries, alongside the development of the Khayal vocal form. Earlier forms of Indian music used different drone instruments — the veena's drone strings, the surpeti (a small bellows-operated drone), and others. The tanpura's current form became standard in Hindustani music from roughly the seventeenth century onwards. In Carnatic music, the tambura (a slightly different instrument of the same family) serves the same function.
In Indian aesthetics, the drone is not background — it is the fundamental. The tanpura's continuous sound establishes Sa (the tonic) as a permanent reference against which every other note defines itself. Without this reference, the raga cannot exist; with it, the finest distinctions of intonation and ornament become audible and meaningful. The tanpura is the ground of being for Indian classical music.