ENTER MUS-HENLEY DA

Don Henley performed earlier this year at the 2017 MusiCares Person of the Year Dinner at the Los Angeles Convention Center in Los Angeles. (Frank Micelotta/PictureGroup/Sipa USA/TNS)

DALLAS — A few weeks ago, sitting in the den of his northwest Dallas manse lined with leather-bound tomes signed by their famous authors, Don Henley was contemplating the price paid for his decades on stage, in recording studios, in airplanes, in hotel rooms.

“I’m beginning to think about it because the health ...” A pause. Henley says nothing, does nothing, without a beat of deliberation.

“The toll is becoming more apparent.” The physical toll, he said; but ... the psychological, too.

The man who has spent a lifetime singing behind a drum kit in arenas and stadiums ticked off a list of ailments and irritations involving the cervical spine, rotator cuffs, ulnar nerve, his throat. The ringing in the ears that can be deafening in a quiet room. The twisted back and tingling hands. The dull pain that dissipates only when it’s replaced by the sudden, terrifying numb.

This went on for a while, until he said it sounded like he was complaining. He brushed off the grim cataloging as something so ... “unnecessary,” he would say. It just comes with doing the job.

“It seems like this is the kind of stuff that I need to just shut up and keep to myself,” Henley said through a small grin. “Because the blessings, if you will, far outweigh the price that I’ve paid.”

Henley, the once-and-forever Eagle, turned 70 on Saturday. There was a concert at the American Airlines Center in Dallas, a career retrospective during which he was joined by famous collaborators, among them Stevie Nicks and Patty Smyth. Joe Walsh and Timothy B. Schmit also were there, representing the band in which the son of Linden, Texas, became famous at the age of 25.

The hometown concert was Henley’s idea, mostly because he wanted something to do the day he becomes a septuagenarian. The last thing he wanted to do was stay home and ruminate.

“Turning 60 didn’t phase me much,” he said. “But 70’s a bit of a different kettle of fish. It’s something that makes you start thinking about how much time you might have left and what you want to do with that time, how you want to spend it. I have a huge bucket list that I’ll probably not get to the bottom of, but we’ll see.”

Before we go on, before this all starts sounding grim and unbearably depressing, it should be noted that Henley is far from locking the doors, drawing the shades and retreating into the quiet darkness. He is still on the road playing epic, never-phone-it-in shows with the re-re-reformed Eagles and with his solo-act band, which Henley says is the best he’s ever had thanks in no small part to contributions from Dallas’ own Chris Holt and Milo Deering, regulars for the last two years.

Henley, who took 15 years to make 2015’s “Cass County,” keeps talking about wanting to make more albums, like the soul record he’s been promising for years. He is also threatening to write a book, his life’s story, but keeps finding reasons to push it off.

“The story’s not over yet,” he said, explaining his reluctance. “I can’t write it from the grave, though, can I?”

So he keeps playing, for hours on end, suffering through the aches, accruing new ones — because it is what he knows, what he is best at, and because it is what the people want.

A couple of years ago, before embarking on the “Cass County” tour, he vowed to keep the Eagles out of the set list. He told me, in this same living room, he didn’t want to be a “human jukebox” spitting out “Hotel California” and “Desperado.” I get the sense now he regrets using the phrase because it diminished the audience that made those songs, and all the others, immortals that will be played for as long as this planet can hang on.

“I always have to keep in mind how important these songs are to other people, to their lives,” he said. “I was going through some old fan letters last night, and there was some incredibly moving stuff from people who had terminal diseases and war veterans who came back injured and how the music has been therapeutic for them and helped them get through tragedy and loss and illness. These songs are much more important than any one of us in the band. The songs are going to live on long after we’re gone.”

He was reminded of that just last week, when, at Dodger Stadium, the Eagles played a full set for the first time since the January 2016 death of Glenn Frey.

He had been Henley’s collaborator and co-conspirator for close to five decades, since they were just the guys in Linda Ronstadt’s backing band. Hours after Frey succumbed to rheumatoid arthritis, acute ulcerative colitis and pneumonia, Henley said he “was like a brother to me.” In the wake of Frey’s death — at 67 — Henley said the Eagles were finished.

“When you’re in shock, you say things, but that’s true — that’s what I thought at the time,” Henley said.

But his manager Irving Azoff told him there were still people who wanted to hear the band perform. Henley said he would only do it under one condition: if Glenn’s son Deacon, now 25, took his father’s place. Glenn’s wife Cindy agreed; so did Deacon.

“We’re not replacing Glenn, because Glenn is not replaceable,” Henley said. “We are adding his blood to the band. We’re keeping it in the family.”

Frey’s death came but a few days after David Bowie’s at 69. And then began 2016’s unforgiving onslaught of musicians’ obituaries.

Henley watched as other friends and heroes began to vanish, among them Merle Haggard, who appeared on “Cass County”; and Leonard Cohen, whose longevity as a touring artist he long admired. Henley, Jackson Browne and J.D. Souther, who co-wrote some of the Eagles’ biggest hits, were at a funeral not long ago in Los Angeles.

“And we laughed and said, ‘The only time we see each other these days is when somebody dies — and next time it might be one of us,’” Henley said. “So all those kinds of things are starting to come into play and starting to enter my thought processes. I don’t want to be morbid about it, but it’s the reality.”

Henley does not expect to tour for much longer — a year, perhaps, maybe two. Life is too short to spend much more time on the road, cramped in airplanes and buses, seeing the world but not experiencing it from the inside of a hotel room.

Not long ago he suggested he might move back to Linden one day to become “the philosophical, intellectual farmer who farms and writes.” And maybe that’ll happen. Or maybe he’ll play with the Eagles until his son Will, just out of high school and a fine musician himself, takes the old man’s place alongside Deacon. He says he reserves the right to change his mind.

“These days, I think about how fortunate I am to have a career that has lasted this long and to still have my health,” he said. “God knows I should have died in 1979 or 1980. And a lot of my peers are checking out now. We just lost Gregg Allman, same age as me. Makes you think. The clock starts ticking louder.”