Calling all carnyx

For every classification of [things] there will be a function {that I've learned about most recently}. For the set [instruments] that function returns a value of the carnyx.

The carnyx was a sort of war trumpet used by Iron age Celts between 200 BC and 200 AD. Its long tube forms an S or integral shape, elevating the bell above the heads of warriors, where it could deliver its frightening clarion across the battlefield. The general shape of the instrument has been known since fragments of one were discovered in 1816. More recent discoveries have allowed researchers to create more acoustically accurate copies. Who knows what it sounded like in the hands and lips of its makers, but there's no doubt it can emit some unsettling tones.