English: The range of a Jew's harp as string harmonics:

“By using the cavity of the mouth as a resonator, each harmonic in succession can be isolated and reinforced, giving the instrument the compass shown. The lower harmonics of the series cannot be obtained, owing to the limited capacity of the resonating cavity. The black notes on the stave show the scale which may be produced by using two harps, one tuned a fourth above the other.”

This file plays harmonics 4, 5, 6, 7, 8, 9, 10, 11, and 12.