jews'-harp, musical instrument of ancient lineage composed of a small metal frame containing a flexible metal tongue. The frame is held between the teeth and the metal tongue is plucked with the fingers. Each jew's-harp can produce only one tone, the quality of which may be varied by modifying the shape of the mouth to emphasize different harmonics of the tone. The musical possibilities may be increased by the use of additional tongues, giving additional tones, and in the early 19th cent., particularly in Germany, jew's-harps were made with as many as 16 tongues. The instrument bears no traceable relationship to the Jewish people. It has also been called jaw's-harp, jew's-trump or jews'-trump.