Iggy Pop has been thinking a lot about death lately. He looks further from it now, at age 68, than he did 40 years ago, when he seemed determined to immolate himself in a blaze of rock'n'roll excess. But facing mortality is the subtext of his new album, Post Pop Depression, which he's hinted might be his last. And sometimes, he just comes right out and says it.

"Is there a heaven for the brave?" he wondered aloud Tuesday night at Keller Auditorium; it was two songs in, and the charcoal blazer he entered with was already slung over his shoulder, returning to his natural state of shirtlessness. "Would I like it? Is it like Vegas?"

Seeing him onstage, maneuvering and contorting that famously lithe physique, looking nowhere close to an almost-septuagenerian, it's hard to imagine he'll find out very soon. But even an indestructible force must confront the void eventually, particularly when it begins to swallow those around them. Pop has seen it happen a lot recently: to his Stooges bandmates, Ron and Scott Asheton, and auxiliary member, saxophonist Steve Mackay; to his old partner in bad behavior, Lou Reed; and of course, to the biggest ghost in the room, David Bowie. Although never mentioned by name in Portland, it's his thin white specter that looms largest over this current tour: Save the brand-new material, and a revisit of his theme to the 1984 film Repo Man, the setlist is taken entirely from the two albums they made together in the '70s.

To a degree, Iggy is the last man of his era standing, so it's understandable that he'd begin to ponder the end, and whatever comes after. But at the Keller, one thing was made clear right away: He ain't dead yet.

Bounding out to "Lust for Life," joined by his new collaborator, Queen of the Stone Age's Josh Homme (who produced Post Pop Depression), and four other Homme associates, that particular message resonated as loud as the big, familiar opening drum beat. What was once a song exalting the dangerous living that probably should have killed him has become, four decades later, an affirmation of survival. Over two hours, it became the night's mission statement: If this really is it for the Great and Powerful Ig, he's going down swinging—and gyrating and pirouetting, and falling backward into the audience, and humping the occasional speaker. It was as much a feat of stamina as the Bruce Springsteen marathon a week ago, but with a heightened sense of live-wire unpredictability. No, he didn't cut himself open or smear peanut butter on his chest like in his streetwalking cheetah days, but there were still moments rarely seen inside the normally mannered walls of the Keller—for instance, when a hand reached up from the front row and grabbed his crotch. Pop, of course, didn't flinch.

For their part, Homme and company, wearing matching red satin jackets, rightfully ceded the spotlight, except for when Pop put the spotlight on them: calling out his "funky drummer," Matt Helders of Arctic Monkeys; leaving them alone onstage to jam the run-out of "China Girl." But they didn't just fade into the background, either. New songs, like "American Valhalla" and the tumbling "Sunday," stomped and grooved as anyone might expect from a Homme-helmed project, and the band brought some of that revitalizing sludge to the Bowie-era material: "Some Weird Sin," "Baby" and the lurching "Mass Production" may have been Queens of the Stone Age songs this whole time.

In the end, though, there was only Iggy. After the house lights went up, following a celebratory run through 1977's "Success," he remained onstage as the rest of the band exited, grinning wide as he flipped a loving double-bird and waving to the crowd, as he did throughout the night. It was uncertain if they were meant as hellos or final goodbyes. Either way, the show confirmed something which once seemed improbable: Against every possible odd, Iggy Pop is going to die old, and leave an exquisite corpse.

All photos by Colin McLaughlin.