The reigning monarchs of the new/old wave of British heavy metal movement, it would be perfectly acceptable for Iron Maiden to rest on their considerable laurels and just pick-slide and fist-pump their way through a seemingly endless cycle of continent-spanning stadium tours. Instead, the band has continued to add new material to their arsenal, fleshing out the nooks and crannies of past glories with expansive, prog-minded efforts like The Final Frontier (2010) and Book of Souls (2015). Clocking in at just over 80 minutes, the epic Senjutsu is another distended late-career triumph, albeit one that requires multiple spins to set up camp in your Homeric metal-craving cranium. Commencing with one of the band's best openers in years, the potent "Senjutsu," treats the prosaic cruelties of war with equal parts melancholy and might. Apart from the nimble "Stratego," which bears the instantly familiar galloping gait of classic Maiden, the ten-song set leans hard into the band's progressive tendencies. Despite an overarching preference for midtempo pieces, Senjutsu never lumbers. The serpentine arrangements and sonic detours into everything from Spaghetti Western-inspired groove metal ("The Writing on the Wall") and maximalist, major key art-rock ("The Time Machine") to lilting folk-metal ("Death of the Celts") show a flair for innovation that artists who've been in the game so long rarely aspire to. Even the lofty Steve Harris-penned closers, the Powerslave-referencing "The Parchment" and the weighty, yet stirringly melodic "Hell on Earth," feel immediate and vital. Bruce Dickinson may not have access to the upper registers of his youth, but his voice is still plenty powerful, and it's become richer with the weariness and wisdom of age. When he wails "Love in anger, life in danger" over the anthemic closing moments of the latter track, it resonates as the story's protagonist is no longer a seeker but a seer.