steel drum

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A metal percussion instrument of Trinidadian origin, fashioned from an oil barrel and having a concave array of flattened areas that produce different tones when struck.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a concave percussion instrument made from the metal top of an oil drum; has an array of flattened areas that produce different tones when struck (of Caribbean origin)