There are differences between sludge metal and doom metal. There are also subtle distinctions between stoner metal and stoner rock. And then there's Big Business, a band that fine-lines these subgenres of subgenres. Drummer Coady Willis (ex-Murder City Devils) and bassist Jared Warren (ex-Karp) don't try to outdo what's already been done -- they just make it cohesive. The act's latest effort, Head for the Shallow, is on the Hydrahead imprint, and that essentially means two things: It's heavy and it's loud. With song titles like "O.G." and "White Pizazz," the disc is not without a little blithe humor reminiscent of early-'90s grunge bands. But blatant throwbacks to the not-so-distant past stop there; traces of the pair's former musical alliances are as smudged as the lipstick on a beer bottle's rim. It feels tacky to even mention their ex-member-of-whoever status. The two may not be piecing together buzzwords to make new genres, but they are creating a name for themselves like nobody's business.