The flexatone was invented in the 1920s. It is a percussion instrument that consists of a small flexible metal sheet suspended in a wire frame that also makes up the handle. Two wooden knobs are mounted on strips of spring steel and attached on each side of the metal sheet. The player holds the flexatone in one hand with the palm around the wire frame and the thumb on the free end of the metal sheet. The player then shakes the instrument with a trembling movement which causes the beaters to strike the sides of the metal sheet. While shaking the handle, the musician makes a high or low pitched sounds depending on the curve given to the blade by the pressure from the thumb. A vibrato is thus produced.