After the Exodus other instruments, perhaps derived from Egypt, make their appearance: the _shophar_, or curved tube of metal or ram’s horn, heard amid the smoke and thunderings of Mt. Sinai,[12] and to whose sound the walls of Jericho were overthrown;[13] the _hazozerah_, or long silver tube, used in the desert for announcing the time for breaking camp,[14] and employed later by the priests in religious service,[15] popular gatherings, and sometimes in war.[16] The _nebel_ was either a harp somewhat larger than the _kinnor_, or possibly a sort of guitar. The _chalil_, translated in the English version “pipe,” may have been a sort of oboe or flageolet. The band of prophets met by Saul advanced to the sound of _nebel, toph, chalil_, and _kinnor_.[17] The word “psaltery,” which frequently appears in the English version of the psalms, is sometimes the _nebel_, sometimes the _kinnor_, sometimes the _asor_, which was a species of _nebel_. The “instrument of ten strings” was also the _nebel_ or _asor_. Percussion instruments, such as the drum, cymbals, bell, and the Egyptian sistrum (which consisted of a small frame of bronze into which three or four metal bars were loosely inserted, producing a jingling noise when shaken), were also in common use. In the Old Testament there are about thirteen instruments mentioned as known to the Hebrews, not including those mentioned in Dan. iii., whose names, according to Chappell, are not derived from Hebrew roots.[18] All of these were simple and rude, yet considerably varied in character, representing the three classes into which instruments, the world over, are divided, _viz._, stringed instruments, wind instruments, and instruments of percussion.[19]