The JEW'S HARP or Jaw's harp is widely distributed among primitive and civilised peoples. At its simplest it is a strip of bamboo cut in the shape of a comb with only one tooth; when made in metal, the tooth or tongue is a separate piece soldered to the frame. In each case the instrument is set between the player's teeth, and the mouth cavity amplifies the sound made by plucking the free tongue of the "harp." It is essentially an instrument for the player's pleasure, being hardly audible to anyone else.
Plate 133 152 Plates from Bonanni's 18th Century "Gabinetto Armonic" Antique Musical Instruments and their Players 1964 Dover Publications N.Y
Daniel AIU Higgs interview and performance with Jew's Harp