Cardinology is a classic-rock record to the bone, nodding to influences that Adams has conjured before but never so well: the country rock of the Grateful Dead and Gram Parsons, the arena anthems of U2. It begins with four killers in a row: "Born Into a Light" prays for faith amid troubles over a Tex-Mex melody, weepy pedal steel and gospel-tinged vocals; "Go Easy" is a breathless love pledge with heartland-rock hooks; "Fix It" is a plea for psychic repair that meshes a slithery R&B groove with a soaring Bono-style chorus; and "Magick" is pure mindless garage-rock pleasure, notwithstanding the geopolitical apocalypse lurking in its lyrics ("You're like a missile strike/Government goes underground/Warhead on legs/What goes around comes around"). Then things settle down a bit — but despite overcooked nautical metaphors on "Sink Ships," they never slack. Cardinology's riveting finale is "Stop," a fragile piano ballad sung in a shaky voice that slowly gains strength and takes flight. It's clearly about rehab, and while rehab rock may be a bit of an oxymoron, Adams — who has reportedly cleaned up — defines a genre here. If it helps undermine some of the bogus junkie myths about hard drugs and creativity, all the better.