The new David Cross album and DVD Bigger and Blackerer was taped during two shows, back-to-back on the same evening at Boston’s Wilbur Theatre. As will be obvious by the packaging (and maybe some of the words here), this title applies to both a CD and a DVD; separate releases in separate formats with the same name. Though both media are housed on a shiny, silver five-inch disc, each is an entity unto itself. And while there is some overlap, each is full of material that appears solely on one or the other. Only by watching the DVD will you learn of Cross’ unique relationship with the deaf community, share his canny insights into the editorial machinations behind the Bible, and marvel at how well a bald, middle-aged white guy can fill out a pair of jeans. Yet one must listen to the CD in order to hear about gastro-intestinal misadventures with his dog Ollie Red Sox, or sing along with “The Sultan’s Revenge,” the swinging, Vegas-style opening number composed by Cross and his good friend Mark Rivers (author of the theme to Mr. Show).