Nagak 나각 螺角 - Korea Flute Instrument

Nagak is a sea shell instrument which is mostly played in korean military processions daechwita. This type of conch horn is played in almost every country on earth where there is one. Such as the Horogai in Japan or the Triton Shell in Greek mythology. Since my focus is on instruments, it is very interesting and surprising that this "natural instrument" is mostly used as a military instrument (for example as a signal to attack).