Gopichand

it works 

The gopichand is made from a bamboo split lengthwise, with the two ends attached to a resonator.

The resonator can be made from a coconut, gourd, metal container, or hollowed-out wood.

The open end of the resonator is covered with skin, and a string is attached to a tuning peg in the bamboo.

The gopichand is played by plucking the string with one finger.