Pokey LaFarge knows he’s no gimmick. Just as there are countless guitar-based groups that recall the ‘60s and ‘70s and blues bands that bring us back to the ‘50s, LaFarge’s acoustic approach sends us back to the ‘20s and ‘30s before electricity powered the music and a man’s guitar chops were all he had. Jack White raised LaFarge’s profile by releasing an album on his Third Man Records. But now LaFarge is where he belongs: on the roots-based Rounder Records. His prewar blues and country swing may not be for everyone, but for those mesmerized by the jaunty rhythms, Something in the Water provides the goods.