Might be one of the oldest bagpipes, but there are hundreds of stringed instruments, bells, drums and organs that predate that, before we get into the really old stuff made of pottery and stone. I've played with a friend who has a cello from the 1670s.

You occasionally see pre-Columbian ocarinas on EBay. Some of them must be for real. I contemplated bidding on one that was supposed to be from 800AD once.