It’s an overcast Saturday morning in Dublin and Flight of the Conchords – AKA Bret McKenzie and Jemaine Clement – and I are in a coffee bar discussing how the pair ended up being in one of the most successful musical comedy bands on the planet when they are not actually fans of the genre.

“I love watching bands play and I love watching comedians perform, but I don’t go out of my way to watch musical comedians,” says McKenzie, the smaller and more serious of the two, with implied heavy understatement.

Clement, the brawnier and gigglier one, agrees: “Yeah, we love doing it, but we wouldn’t watch it.” He makes a delighted honk of a giggle.

Many others, however, do watch it – so many that I couldn’t get into their show in Dublin the night before. All 13,000 tickets had sold out for the first night of the band’s rescheduled tour, which was postponed after McKenzie broke two bones in his hand earlier this year. (“I fell down some stairs. It’s not a very good story, is it?” “Yeah, you should work on coming up with a funnier one.”) The rest of the tour sold out immediately, such is the public’s love for the Conchords’ supremely skilful and loving musical parodies, including Inner City Pressure, their take on West End Girls by Pet Shop Boys (sample lyric: “No one cares, no one sympathises / You just stay home and play synthesisers”) and their anti-seduction song, Business Time (“Then you go sort out the recycling / That isn’t part of the foreplay / But it is very important.”) They have had to add on some dates to meet the demand, which is not bad going for a band that just celebrated its 20th anniversary, but hasn’t released an album in more than a decade.

The five best Flight of the Conchords songs Read more

Despite themselves, Flight of the Conchords are still huge, although, heaven knows, they try not to be: they rarely give interviews and tour only when they feel like it. They are the only band I have ever interviewed who undersell themselves, repeatedly underestimating how many tickets and albums they have sold. Their main complaint about this tour is that the venues are too big. “I like an opera hall … 1,500 people. Perfect,” says McKenzie who, alas, finds himself playing stadiums.

“Fame is only an impediment,” Clement agrees.

Come on, surely they get something good from fame?

“Mmm … sometimes someone gives you a free ice-cream.”

Another thing their fame bequeathed them was the status of sex symbols. Today, McKenzie, 41, and Clement, 44, look a little more grizzled than they did on their eponymous sitcom, which they walked away from in 2009. A dad-like steadiness to their bearing has replaced the floppy late-twentysomethings they once played on TV. (Both are married with children and live with their families in Wellington; Clement has a nine-year-old son and McKenzie has three children, ranging in age from three to eight.) Back in the 00s, when they won a Grammy and their albums were in the Top 20, there was much talk about how the pair represented a new kind of anti-sexy sex symbol; I have friends who still, on a quiet Saturday night, crank up some of their old videos, such as Sugar Lumps, in which Clement and McKenzie gyrate all over a Chinese restaurant as they sing about how women love to stare at what they call “the family jewellery”. (“My dungarees make [the ladies] hun-ga-ree / They’re over the moon when I don pantaloons.”)

If they don’t care for fame, do they enjoy being lusted over by the ladies? McKenzie rolls his eyes so hard he nearly falls out of his chair.

“We’re retired sex symbols,” Clement says with a snort.

Clement has described himself, not inaccurately, as resembling “an ogre in a library”. When trying to describe McKenzie, he opts for a similarly Middle-earthian comparison: “If you go to the set of Peter Jackson’s Lord of the Rings when they’re filming an elf scene, you will see 100 people who look exactly like Bret.” (As it happens, McKenzie did play an elf in The Lord of the Rings and The Hobbit; his wife was working for Jackson at the time.)

Facebook Twitter Pinterest Clement and McKenzie on their HBO show, Flight of the Conchords. Photograph: HBO

When McKenzie and Clement ended their TV show – set and filmed in New York – after two critically acclaimed series and moved back to New Zealand, it looked as if Flight of the Conchords may have been a mere flash in the hipster pan. And yet, even aside from the duo’s enduring personal appeal, their TV show has proved to be so influential that it feels as if it never really went away. Broad City, Search Party and Girls were all clearly influenced by Flight of the Conchords’ take on quirky New York bohemia, and viral lo-fi music videos that have become a staple of US late-night TV shows often feel like lesser versions of the songs McKenzie and Clement performed on their show and still do on stage. They both shrug when I ask if they think others have ripped off their vibe.

“We borrowed from other stuff, too,” says Clement.

Like what?

“I don’t know. Bert and Ernie?”

And yet when Flight of the Conchords debuted on HBO in 2007, it looked like nothing else anyone had ever seen. They played a pair of New Zealand musicians called Bret and Jemaine whose banal lives contrasted with the ridiculous grandiosity of their music videos, which would suddenly interrupt a scene as the characters broke the fourth wall and sang to the viewers. It was like an MGM musical for Gen X and millennials, but with more Prince references and songs about failed sexual encounters. At the time, the show was seen as part of the new wave of comedy of embarrassment, along with Curb Your Enthusiasm and The Office. But Flight of the Conchords always had more optimism and innocence than those shows; it certainly had none of the cynicism that was then so popular in comedy.

“It’s quite hard to grow up in New Zealand and be cynical. It’s just too beautiful,” says McKenzie.

The combination of their New Zealand cheerfulness with the sharpness of the songs created one of the most original and unlikeliest breakthrough TV hits around. But given how much they sang about sex on the show and how quickly social mores in comedy have changed, I wonder if they have had to change any of the songs for the tour.

“Well, it’s not like we do Blurred Lines – we don’t generally sing about forcing people into sex,” says Clement, and laughs at the thought. “But, yes, there were a couple of old songs we looked at and were like: ‘Can we still say that?’”

Like what?

“I’m not going to tell you.”

McKenzie jumps in: “Also, thinking back to the making of the show, when we were casting, they would only send us white actors for roles, even though there was no description of race in the script.”

“Especially if it was for a female role,” adds Clement. “And that has all changed now. Now, if you write a show, people are like: ‘You need more women.’ It definitely wasn’t like that before. And,” he adds apologetically, “we are a very male-dominated band.”

Clement and McKenzie met at university in Wellington, when they were in a theatre group and realised they were the only two in the troupe who couldn’t play guitar, and so decided to write songs to learn.

But how do you go from a New Zealand university theatre group to an HBO hit show in a decade? The Conchords are so averse to trumpeting their successes that their answer takes some decoding.

Facebook Twitter Pinterest Nominated for the Perrier award in 2003. Photograph: Murdo MacLeod/The Guardian

“So, we were at Edinburgh and after that we went to the BBC,” begins Clement. (Translation: they were nominated for the Perrier award at the Edinburgh fringe in 2003 and, on the back of that, were signed to write a series for BBC Radio 2, where they started sketching out the show.)

“We grew up watching BBC shows, so going to the BBC building was way more exciting than going to America,” says McKenzie.

But the BBC building is pretty crappy, isn’t it?

“Yeah. We were like: ‘What? This is just like home!’”

“And the lunches were really, really terrible,” adds Clement solemnly.

So you got an HBO series on the back of a BBC radio series? Do people at HBO listen to the radio?

“No, they definitely don’t. We’d talk about the radio series to them and they’d be like: ‘Radio? Like in the 1950s?’” says McKenzie.

“‘You stand there with microphones banging a coconut?’ We absolutely had that conversation,” says Clement.

What in fact happened was they performed at a comedy festival in the US and from there were signed to HBO. A dream come true for most comedians, but a nightmare for them. Suddenly, instead of working at their own pace, as they always had done, they had to work all the time under enormous pressure. When HBO signed them for a second series, they nearly collapsed with anxiety. They told their agents not to tell them what they were being offered for a third series so they could walk away, which they did.

Facebook Twitter Pinterest The pair in their far-off HBO days.

Were they tired of working together?

“We were tired of working together,” says Clement.

“Yeah, it’s not like we were tired of each other’s company. It just wasn’t fun,” says McKenzie.

A large part of the Conchords’ appeal has always been how low-key and laid-back they seem. I can testify that this is not an act. The last time I met McKenzie was in 2012 at the Oscars. I spotted him after the ceremony with his wife, surrounded by hundreds of preening celebrities, casually holding the Oscar he had just won for best original song, for Man or Muppet from The Muppets. He looked – and there is no other way to put this – bored. Boredom was replaced with vague terror when I ran up to him and gushed about what a fan I am. Today, I belatedly apologise for my unseemliness.

“Yes, I’ve been waiting six years for you to say you’re sorry,” he replies without missing a beat.

Did he enjoy the Oscars at all? Because it didn’t really look like it.

“Well, they made me do 500 interviews. Five hundred,” he shudders at the memory.

The irony for Conchords fans is that what makes them appealing is also what makes them elusive: they really don’t care about fame and fortune, which is why they walked away from their show at its peak and why they don’t do many tours. It’s an attitude that mystified the producers at HBO and one the Conchords put down to being from New Zealand.

“The first time I went to London and New York, I realised: oh my God, you need so much money to live in these places. Whereas in New Zealand, at least when we were growing up there, money was not part of the equation, not in the same way. So making money is not such an imperative part of life,” says McKenzie.

As for fame, there is a culture in New Zealand of not wanting to stand out – and no one in New Zealand ever really believed they were internationally famous anyway, says Clement. The only US talkshow people watched in New Zealand was The Late Show With David Letterman, so even though the Conchords were appearing on big US shows in the early 00s, such as Late Night With Conan O’Brien and The Late Late Show With Craig Ferguson, none of their friends and family saw them. Finally, in 2007, they were booked to appear on Letterman. At last, people back home would know how well they were doing. Except, on that day Letterman was bumped off the New Zealand TV schedule because of a big All Blacks game.

“It was for the best,” Clement says contentedly.

For a while, they lived in the US, but quickly realised it was better to be in Wellington. “In LA, you can get kinda swept up in the industry, like: ‘Oh I’m supposed to be doing this thing,’” says McKenzie. “Then you go home and it’s like …”

“You don’t have to,” says Clement.

Facebook Twitter Pinterest Live on stage in 2013. Photograph: Tim Mosenfelder/Getty Images

“Yeah, they don’t even care what movies are on. So you can just do what interests you. That’s the other thing about being from New Zealand: there’s no industry there to speak of, so everyone does a lot of different jobs,” says McKenzie, whose father was an actor, singer, lawyer and horse trainer.

“The career paths aren’t as direct as they are in London and New York,” agrees Clement, whose father worked in an abattoir and now makes stained glass windows and whose mother started out in a cheese factory and now works in a garden centre.

McKenzie’s mother was a ballet teacher and he credits her with getting him interested in music.

“New Zealand is so small that any time anyone does anything, the papers will call up that person’s parents for a quote. I don’t think that happens in London, does it?” he asks McKenzie.

Not really, I say.

“Right, so when we were going to the Emmys, the papers all called up my mum to ask what we would be wearing. And she said something like: ‘I don’t know. I think they wore T-shirts on the plane. The headline was ‘Conchords to wear T-shirts to the Emmys’,” he says, equal parts amused and bewildered.

“It’s not even what she said,” says Clement, defending Mrs McKenzie’s honour.

Once they wrapped up the TV show and decided to moved back home, they briefly had a plan to roll off the plane wearing huge fur coats and giant gold chains, strolling through Wellington airport like Hollywood cliches on their way to shoot MTV Cribs.

“But we just couldn’t,” Clement says, blushing at the thought. Singing songs about sexual failure for 20 years: fine. Flaunting one’s success, even in jest: unthinkable.

Since then, they have enjoyed individual successes, in proportions they like: Clement has appeared in Men in Black 3, written a sitcom for a New Zealand TV station and co-directed the vampire mockumentary What We Do in the Shadows. As well as winning an Oscar and playing an elf, McKenzie has been working on screenplays and doing some more work with the Muppets.

This is the other problem for Conchords fans: as much as they love the band and show, for McKenzie and Clement, it was always a hobby, one they would only do as long as it was fun.

“I mean, this was all just a side project to learn guitar,” Clement says.

“My entire career is a side project,” says McKenzie.

“Yeah, I’m still waiting for the main project,” agrees Clement and he gives another giggle of delight.

Flight of the Conchords are touring the UK in June and July. Tickets: MetropolisMusic.com