The jaw harp (or Jew's harp) is a 'lamellophone.' It consists of a flexible metal or bamboo tongue attached to a frame. The player places the frame against their teeth and plucks the tongue. The instrument itself has almost no volume; the player’s mouth and throat act as the resonator. By changing the shape of their mouth and moving their tongue, the player filters different overtones, effectively 'singing' through the vibrating metal. It is one of the oldest and most geographically widespread instruments in the world.