A bansuri is traditionally made from a single hollow shaft of bamboo with seven finger holes. The six hole instrument covers two and a half octaves of music. The bansuri is typically between 30 centimetres (12 in) and 75 centimetres (30 in) in length, and the thickness of a human thumb. One end is closed, and few centimeters from the closed end is its blow hole. Longer bansuris feature deeper tones and lower pitches. The traditional design features no mechanical keys, and the musician creates the notes they want by covering and uncovering the various finger holes.