“This is what happens when you get old,” Pete Townshend said with cheerful resignation.

Townshend, the “lead guitarist, chief songwriter, and presiding genius” of the Who, as the critic Ellen Willis once wrote, had knee replacement surgery earlier this year. Roger Daltrey, the band’s singer, announced in April that he’s losing his sight and his hearing — though not, he’s quick to emphasize, his powerful tenor.

So on Aug. 16, the Who began what they call a farewell tour of North America. Townshend, 80, and Daltrey, 81, formed the group with Keith Moon and John Entwistle, who died in 1978 and 2002. The band has mustered only two new albums in the last 40 years, but through the ’60s and ’70s, the Who treated rock both as an art form and a cathartic communal ceremony, consistently stretching the limits of how thoughtful and expansive the music can be. The Who’s cinematic songs even spawned a Broadway musical (“Tommy”) and a film (“Quadrophenia”). Daltrey’s macho roar gave body and vigor to Townshend’s words, and in concert, they created an uncontrollable source of energy that could explode in volume or mayhem.

In separate interviews, there was a stark difference between Townshend and Daltrey, an odd couple who’ve been open, even boisterous, about their differences. The infamously articulate Townshend, in a video interview from his recording studio in the Vale of White Horse, 70 miles west of London, was philosophical and digressive as he reflected on the Who’s career.

Daltrey, on the other hand, was concise and playfully gruff, a man of certainties rather than questions, as he talked from a hotel room in Florida. “I’ve just gotten out of bed and I’m having breakfast,” he announced. It was 4:30 in the afternoon.

These are edited excerpts from the conversations.

The Who’s first farewell tour was in 1982, and there have been other “final” shows since then. Why should anyone believe you this time?

PETE TOWNSHEND Are you suggesting we’re swindling the public? [Laughs] The fact is, we are willing to swindle them. That’s what we’ve done our entire life. Why stop?

The 1982 tour was a mistake. I was in terrible shape, with family troubles, and I needed a sabbatical. I wrote to the music newspapers and said, “I’m stopping work with the Who.” We already had a tour booked, and when it started, I realized it was being billed as the final tour. I should have objected, but I didn’t. The album I’d just written for the Who, “It’s Hard,” is one of our weakest. I didn’t feel I was able to write great songs for the Who. I didn’t know who we were anymore.

With respect to whether Roger and I will work together in the future, I hope so. If he doesn’t want to do a Who album, I’d love to write songs for him for a solo project.

You were partly joking, but do you think pop music is a swindle?

TOWNSHEND When I wrote the Who’s first hit, “I Can’t Explain,” a deputation of five boys and a girl at the Goldhawk Social Club, where we used to perform, said: “That’s just it — we don’t have the words. We can’t explain. We want you to write more songs like this.” And I realized I’d been given a fantastic job, which is to speak for this audience. Funnily enough, that ratio of five boys to one girl was what the Who ended up with in its audience. We performed mainly for young men, then for fat, older men — fat, balding older men! Bless us all.

Those first Who songs, like “My Generation” and “Pictures of Lily,” were tied into giving our audience members a sense that they’re not alone. So for me, rock music was hugely important.

The swindle starts when you become a property and don’t belong to your fans anymore. You belong to record companies, to promoters, to managers. The audience worships you for what you’ve done years before. They’re not interested in anything new. For Roger and I, it’s difficult to do anything other than feel like we’re a Who tribute band.

After the Who played a London concert in March, Zak Starkey, who had been the drummer since 1996, was fired. Why?

TOWNSHEND I don’t know. I’ve always been open in saying that Zak is not my favorite drummer. But neither is [expletive] Keith Moon, you know? [Laughs] My favorite drummer is Simon Phillips and my second favorite is Kenney Jones. Roger didn’t like either of them!

What did Roger bring to Who songs that you couldn’t if you’d sung them yourself?

TOWNSHEND He’s gone through phases, hasn’t he? In the early days, he just growled. He sounded like Howlin’ Wolf, then “Tommy” came along and suddenly he was singing like a choirboy. Whether you like his voice or not, he’s a great dramaturg.

Is it fair to say that Roger’s musical tastes were more conservative than yours?

TOWNSHEND When John Entwistle wrote “Had Enough,” he and I decided it would be nice to get Ted Astley, my father-in-law, to write a string arrangement. Roger hated the strings. He and Glyn [Johns, the band’s producer] got into a row. Glyn stuck his nose in Roger’s face, and Roger nutted him. That was the last we saw of Glyn! The argument was because we were experimenting with our sound. Roger felt: “We have it already. It’s good enough.”

I was a geeky young kid with a big nose who wanted to be an artist or a journalist, not play in a rock band. My father, a brilliant musician, didn’t believe in me and allowed my grandmother to buy me a [expletive] old guitar that I couldn’t play. Some of my guitar-smashing antics probably started because it had become a symbol for me of the way my father had not considered me worthy of a decent instrument.

Reading between the lines, it seems like more dates might be added to the farewell tour if you and Roger are in good health.

TOWNSHEND Not me — I’ll be fine. I went through a period of feeling very depressed. And when I had the knee operation early this year, I got readdicted to painkillers. This is the way rock stars die, OxyContin.

I’d gone through severe alcohol addiction for many years, then narcotics. I’d been clean for over 30 years. I called a close friend who’s working for a recovery clinic in Spain, and he got my head sorted out. I’m feeling really good at the moment.

It’s in Roger’s hands. If we don’t extend, would we be in breach of contract? Would we be in swindle-land if we came back and played all those important venues we’ve left off the list, like Duluth? [Laughs]

I’m 80, I don’t like being away from my family, my studios, my dogs and my friends. I’m not looking to spend the next five years of my life waiting to [expletive] drop dead on the stage.

The end of the tour could give Roger and I permission never to call each other again. I hope that doesn’t happen.

You mean you and Roger are bandmates and business partners, and when the Who is over, you’ll find out whether or not you’re also friends?

TOWNSHEND That’s what I’m saying. If we stop, the Who brand will continue. We’ll be avatars in a hologram show where guitars get smashed, and people dress in Union Jack jackets and pretend to be rock gods. It will all be managed by Giles Martin, because he’s bored with [expletive] around with the Beatles. And it will be bigger than “Jersey Boys.”

Roger, how is your health?

ROGER DALTREY I’ve got a bit of a shoulder rotator cuff problem, from swinging the mic too much, but the vocals are better than ever. That’s all I care about.

Have you changed the way you tour, to accommodate your age and condition?

DALTREY This sounds like a doctor’s appointment. [Laughs] I have an off day after every show. We’re saying farewell because touring is grueling on the body. Also, the ticket prices are ridiculously high. We’re not giving up as a band. We might do a couple of residencies. Hopefully, Pete and I won’t stop making music.

He said he wants to keep writing songs for you.

DALTREY I would love to write songs with Pete. I wanted that for a long time. As good as his songs have been, who knows what might have been if we’d collaborated?

How has he responded when you mentioned writing together?

DALTREY “Go away.” He wanted to keep it to himself.

Do you want to make another Who album?

DALTREY No, there’d be nothing in it for me, unless I co-wrote the songs with Pete. Our last album, “Who,” cost me money to make. By the time I paid for petrol and all that, I lost money.

Why was Zak Starkey fired? Even Pete doesn’t know.

DALTREY Zak was never fired. At the show in London, the sound of the bass drum was looping back on itself, which wipes out your ability to pitch. You can’t hear the note. I was pointing at the drums, trying to signal my sound man to turn the [expletive] thing down. People thought I was having a go at Zak.

We wanted to go back to the raw sound we had 30 years ago, and sometimes the energy of a band needs refreshing. The Who are Pete and Roger — everybody else is a session player.

Other than the Who, do you and Pete have anything in common?

DALTREY Pete lives a totally different life to me. He’s into boating and is a really serious sailor. He had all the publishing money for years. I made my living on tour, and when we didn’t tour, I had to get acting jobs to fill the gaps. I’m a down-home-in-the-mud farmer. We’re chalk and cheese.

Over the years, his melodies became more grand, didn’t they? “Love, Reign O’er Me” has some high notes and intervals he hadn’t written before.

DALTREY He didn’t write those high notes, I did. That last high note, the scream, it’s not on the demo. Pete sang it as a gentle love song. I sang it as passionate. To me, it was an orgasm.

Has your understanding of Who songs changed over the years?

DALTREY Certain ones, yes. We were a pop singles band, like Herman’s Hermits with a rough edge. [Laughs] But the early records were ahead of their time. “I’m a Boy” is about a woman who had quadruplets and wanted four of the same sex, but one was a boy and she refused to believe it. That was 1965. With the trans issues today, it was very ahead of its time.

What would you like as the last song the Who ever plays onstage?

DALTREY I don’t know. Does it matter? I think it will be “The Song Is Over,” but I’m going to write another verse.

The Who is famously louder than other rock bands. Did that cause your hearing loss?

DALTREY Most of the damage to my hearing came from working with sheet metal, not from the Who. I was grinding welds on belt guards in a factory for eight hours a day, with no ear defenders. But I think back to that as some of the happiest days of my life. The people were tough as old boots but there was a lot of humanity in it.

Do rock bands leave a legacy when they retire?

DALTREY No. It’s just a silly little rock band. Do you think a concert is important in terms of the planet? Come on.

A show can be silly but also inspire people, can’t it?

DALTREY I hope it does, but that’s not in our remit to think about. What the Who will mean in the future, I don’t know. I’m not a magician.