Over the course of their first three albums, Vancouver power duo the Pack A.D. put increasingly less emphasis on their blues influences and more on their rock & roll swagger, and now that they're up to album number five, they've evolved into a stripped-down but muscular rock & roll machine, but they've also added just a dash of pop hookiness to their formula. Make no mistake, 2014's Do Not Engage is full-on rock & roll and clearly proud of it -- Becky Black lays out big clouds of fuzzy six-string goodness and can conjure guitar and bass sounds at once with the élan of Scott Lucas himself, while drummer Maya Miller attacks her kit with the gleeful ferocity and relentless accuracy of a true master. But cue up "Big Shot" and you'll hear a tune you can actually dance to, while "The Water" evokes the clean, echoing surfaces of early Suicide (who were always a lot catchier than anyone wanted to admit), and the stutter-step of "The Flight" sounds plenty sophisticated for a band most often celebrated for its minimalism. As a vocalist, Black is still in her element when she's running her larynx like she pummels her guitar, but on "Needles" and "Loser," she demonstrates how much nuance she can put into more dynamic numbers, and "Stalking Is Normal" shows the Pack A.D. haven't lost their Blues Power when they feel it suits their purposes (not to mention their knack for writing smart, artful, and pointed lyrics). Jim Diamond's production allows Black and Miller to sound as mighty as they want to be without smothering the artful touches the Pack A.D. have added to their arsenal; it's not common for a band to rock this hard and sound this smart at the same time, and the fact they've managed this accomplishment with a mere two people confirms Do Not Engage is both a solid dose of rock action and a model of modern efficiency.