Ektara and gopichand: one string percussive instrument from India
The ektara is simple yet cool rhythmic/percussive folk instrument and has one single bowstring used mostly by wandering bards and minstrels from India and Bangladesh (called Baul), and when striked by the hand,the scale/pitch is changed too like in the african talking drum. The name Ektara comes from the Hindi and Bengali and means "Ek" means one, "tar" string. It is also known as "Gopichand" (or gopiyantra)
There are different variations in the construction. Pressing the two halves of the neck together pushes the peghead away from the body, thereby tightening the string and raising its pitch. The modulation of the tone with each slight flexing of the neck gives the Gopichand its distinctive sound. There are no markings or measurements to indicate what pressure will produce what note, so the pressure is adjusted by ear. This one stringed instrument provides a range of deep sounds, in one long slur.
The length differes being 2-3 feet i the most common measure and consists of bamboo that is split through most of the length. The two ends are pried apart and attached to a resonator made of coconut, gourd, a metal container or a hollowed out cylindrical section of wood. The open end of the resonator is covered with taught skin and a string penetrates the centre. This string is attached to a reinforced section in the centre. This string then passes through the hollow of the resonator and attaches to a tuning peg located in the bamboo.
The sound of the gopichand is most distinctive. There is a peculiar bending of the pitch as the two legs of the bamboo are squeezed together by the left hand while the right hand plucks the string.
Below you can see a video showing how it's played and its overall sound.