I think, in slight contrast to Poppagator, that Zachary Richard should not be called a zydeco musician(because he doesnt play zydeco, basically). But he could be called Creole, according to some meanings of the word. Though not in the current meaning of the word in a Louisiana music context: because it now tends to be used to refer to the pre-zydeco black French music(Bois-Sec Ardoin, Lawtell Playboys, JC Gallow etc).
   Having said that, I may be talking bollocks because I havent heard him for years, and maybe he's started playing zydeco recently. Anyway, whatever you call him,he's well worth a listen!