Although the mouth harp is often associated with bluegrass music, its history actually goes back thousands of years. A version of this simple musical instrument exists in nearly every culture in the world. It might have originated in the third century B.C. in China, though this is uncertain. In modern times, it has been used on recordings by The Beatles, The Who, Red Hot Chili Peppers and other popular rock bands as well as in movie soundtracks such as the one for "A Fistful of Dollars." Even after several millennia, this simple instrument remains popular throughout the world.
The mouth harp consists of a flexible tongue, usually made of metal or bamboo, held within a frame. The frame is held firmly between the teeth while the player strums the flexible tongue to produce a sound that is then amplified by the mouth and jaw bones. Movement of the mouth and tongue can change the pitches so that a melody is produced. Although the mouth harp is simple in construction and use, much practice is required to master its full potential. Amateurs often produce copious amounts of saliva while learning to play, leading some to refer to the instrument as a "juice harp."
The mouth harp has gone by numerous names throughout history. In many cases, a different name was assigned with each cultural tradition. Among the most common names are Jew's harp or Jews' harp, Ozark harp or jaw harp.
The term "Jew's harp" has become out of favor in recent times, because some feel it is derogatory. However, no one is certain how the instrument received that name in the first place, though it is possible that Jewish merchants in medieval times brought the mouth harp to areas of Europe. Other theories suggest that the name is a corruption of other common names for the instrument such as the French jeu-trompe, meaning "toy trumpet." Some have suggested that the term "Jew's harp" is derived from "jaw harp," but the term "jaw harp" has come into usage only since the late 1700s or early 1800s, and the term "Jew's harp" is much older.
Throughout history, the mouth harp has been constructed of various materials and constructed in different shapes. Today, it is most commonly made of metal with a key-shaped frame. The key shape is reminiscent of ancient harps, lending another theory to the origin of the term "mouth harp" or "jaw harp." With its role firmly established in popular and traditional music world-wide, the mouth harp undoubtedly will continue to be a popular instrument in years to come.