Ravi Shanker playing the sitar.
A sitar is a plucked string instrument from India that has a wide neck, frets, steel strings, and gourds as resonating chambers. In addition to the strings plucked by the player, the sitar has a set of strings that vibrate sympathetically when notes to which they are tuned are played on other strings.
The sitar's main soundbox, made from a gourd with a wooden soundboard, flows into a wide teak neck bearing about 20 moveable brass-bar frets that curve away from the hollowed neck, which often has an extra gourd resonator attached near the top. The three or four playing strings can be pressed deeply between the frets and slid sideways across them to bend notes. Running alongside them are three or four drone strings. These are all attached to large tuning pegs, and the main playing strings have fine tuners – beads that slide across the soundboard near their anchor point on the soundbox.
Nine to thirteen sympathetic strings of different lengths run across their own bridge under the frets to tuning pegs along the neck. Instead of of the bridges being a clean edge as is usual on many lutes, the strings pass over a wide and nearly flat bone surface (actually very slightly and critically curved, and slightly angled), producing the characteristic sitar sound.
The surbahar is a larger, lower-pitched form of sitar, with long, rich sustain and strings slack enough for a note to be bent as much as an octave at a single fret. The tampura or tanpura is like a stripped-down sitar – just four strings, no sympathetic strings, no frets – that provides a steady drone behind the sitar or other Indian solo instruments.
The sitar began to develop in the eighteenth century, the surbahar was invented in the nineteenth. An instrument with a longer history than either is the saraswati vina, the leading stringed instrument of Carnatic (south Indian) music. Like the sitar, it has a broad neck, flowing from a soundbox, with a buzz-inducing bridge, but it has no sympathetic strings, and thus has much less sustain than the sitar. The frets are not adjustable, but are attached at the peaks of the scallops on the fingerboard. Four melody strings run over them, and another three shorter rhythm-drone strings run from the side of the bridge and part-way along the side of the neck to tuning pegs. There is a top gourd, but this – probably remnant from the twin-gourd-resonated zithers – has no acoustic purpose; it serves as a support for the instrument, resting on the cross-legged player's left thigh. The chitra vina is an unfretted version, played with a slide like a Hawaiian or steel guitar, and unlike the saraswati vina it has sympathetic strings.