As an encyclopedia, we have to reflect the world as it is, to the extent possible. I can accept that Pharrell Williams (although I've never heard him) sings like a countertenor, and could theoretically be called a countertenor. The truth, however, is that nobody else actually calls him a countertenor. I'm of the opinion that we, as an encyclopedia, should reflect the terminology as it is actually used by people. Not doing so is misleading.