What breaks the ice between Frank Turner and Iron Maiden's frontman Bruce Dickinson is not the large tattoo of Iron Maiden's undead mascot etched for ever into the back of Turner's calf. Nor is it the news that Turner won his round of Celebrity Mastermind with Maiden as his specialist subject. It isn't even Turner's confession that he made a wish, while cutting the cake at his 12th birthday in 1993, that Dickinson would one day rejoin the band he left that year, and hence feels personally responsible for Dickinson's 1999 return. No, what really does it is the fact that both acts have produced their own brand of beer.

"Brilliant!" Dickinson enthuses, backstage at Copenhagen's Copenhell festival in black shorts, hoodie and wool hat. "Have you got any?" Not that he is drinking today – he's flying his plane later.

For more than 30 years, Dickinson has teetered on the edge of rock'n'roll ludicrousness. When not fronting the fire-spewing, animatronic schlock-horror squealfest that is Iron Maiden, he has spent time as a commercial airline pilot, international fencer, TV presenter and first world war dogfight re-enactor in a show he is bringing to this year's Sonisphere festival at Knebworth in July, ahead of Maiden's headline set.

Turner – folk/punk troubadour turned arena rabble-rouser and lifelong Maidenhead – has flown in from the US to meet and interview Dickinson ahead of their dual appearances at Sonisphere, and he is feeling a little jumpy. "They were the first rock'n'roll band I ever fell in love with," he explains.

"I was a kid, music wasn't a part of my life and then I heard Iron Maiden and everything flipped instantly. My dad bought me a copy of Killers on cassette from Our Price at Waterloo station on his way home from work and he genuinely seems to believe that was his major parenting error to this day, because everything in my life changed when I heard that record. I think they are unquestionably one of, if not the, best live act in the world. They've done 15 studio albums and of those I'd say at least 10 are stone-cold unimprovable classics, which is a pretty incredible hit rate for any band."

Dickinson is in convivial mood so, cracking open a bottle of Maiden's Trooper ale, Turner goes straight for the gullet of his new arts media paymasters.

Bruce Dickinson performing in 1983. Photograph: Ebet Roberts/Redferns

FT: I wanted to start off talking about legacy and public perception. You guys are on nearly 60m records sold worldwide. By contrast, Elvis Costello has sold 12m albums. I'm a big Elvis Costello fan but in terms of public perception and particularly the arts media perception, some people take him more seriously. Do Iron Maiden care?

BD: Fundamentally, no we don't. To use a farming analogy, we have our field and we've got to plough it and that's it. What's going on in the next field is of no interest to us; we can only plough one field at a time. We are unashamedly a niche band. Admittedly our niche is quite big.

FT: That's my point. People talk about cultural importance, but in some ways I think the impact that Maiden has had on music has been infinitely more than Elvis Costello's had.

BD: The difference is, with the greatest respect to Elvis Costello, the way people think about him is not quite the same as [the way] they feel about Maiden. If you're a rabid supporter of a football team and you believe passionately in that team, the fact that they have a couple of off seasons doesn't stop you supporting them. As long as they maintain the integrity and don't take the piss. They can play appallingly as long as they're trying hard, and you'll forgive them. If they do it repeatedly over a period of years and then acquire a manager that makes everybody wear pink lipstick and a strange tutu then you may consider your allegiances.

FT: I want to see more representation of Maiden on the South Bank Show.

BD: Yeah, but I would personally feel a bit like a lab rat in a cage where somebody comes along and says [adopts boffin voice]: "Oh, here's a specimen, here's a heavy metal chap who's got a brain, let's have a look at him closely … Let's find out why he likes this heavy metal stuff. Seeing as he has a brain he should be liking Elvis Costello!" The broadcast and TV media fail to get to grips with why the fans of the music like the music. Why do millions of people like Lord of the Rings movies and don't necessarily go and watch Gwyneth in a romcom? Answer: because they're fucking good! Because they tell a great story, because they're exciting, they've got some characters.

FT: Right, but there's a kind of snobbish cultural gatekeeping going on. Metal, by some people, is considered a lesser art form but I feel he only way you can judge cultural impact is by the number of people that are into it.

BD: The closest the "art establishment" ever came to embracing metal was punk. The reason they embraced punk was because it was rubbish and the reason they embraced rubbish was because they could control it. They could say: "Oh yeah, we're punk so we can sneer at everybody. We can't play our fucking instruments, but that means we can make out that this whole thing is some enormous performance art." Half the kids that were in punk bands were laughing at the art establishment, going: "What a fucking bunch of tosspots. Thanks very much, give us the money and we'll fuck off and stick it up our nose and shag birds." But what they'd really love to be doing is being in a heavy metal band surrounded by porn stars."

FT: I haven't seen any porn stars today.

BD: I'm 56 this year, maybe it's beyond me.

FT: One of the things I like about Maiden is that it's unpretentious, energetic, aggressive music for people that don't give a fuck about prevailing fashions and trends.

BD: All this shit, in the 60s and 70s, did not exist. There was music and that was it. It was no crime against God to have a ZZ Top album next door to a Motörhead album next door to a Simon & Garfunkel album next door to whatever. Nobody went: "That's fucking weird." Then, as magazines and radio stations proliferated and they started to compete, so they started to segment their audiences to sell themselves. In doing that, of course the bands started imitating media life. Bands started crafting their music, thinking: "I'll do this because that's the sort of thing Radio 1 will play, I'll do this because that's the kind of thing that that journalist likes." And it's just shit.

Iron Maiden in front of their Boeing 757. Photograph: Newspix/Rex Features

FT: Does Maiden still have a bucket list?

BD: I can't be bothered to have those big, self-congratulatory moments. People say: "What's it like standing onstage in front of quarter of a million people?" I say: "I really can't tell you actually because I'm too busy." You have no time to stand there and go: "Let me just stop thinking about the song, stop performing and let me just look at all these people looking at me … OK, thank you very much!" I see these wankers onstage at places like fucking Glastonbury wandering around as if they had a mirror attached to themselves, gurning for the fucking cameras and paying no attention whatsoever to that kid in the front row.

FT: Who works a minimum wage job to save up for a ticket …

BD: Not at Glastonbury he doesn't, he's living in his air-conditioned yurt and probably working for the BBC. But look them in the fucking eyes, y'know? We should be self-obsessed; actually we're audience-obsessed. That's what makes the difference between Maiden and everything else. I'm not interested in being famous. Fame is the excrement of creativity, it's the shit that comes out the back end, it's a by-product of it. People think it's the excrement that you should be eating. It's not. It's the creativity and the audience and being there in the moment.

FT: I've never understood the rock'n'roll super-puffed-up ego thing simply because for me, the business of being a performer and being onstage every day is an opportunity to make an arse out of yourself, deliberately or otherwise. I once punched myself in the nuts in front of 10,000 people in Italy trying to swing the mike around.

BD: At 17 or 18, loaded with testosterone, you don't have much sense of being able to take the piss out of yourself. So if something goes wrong onstage it's like: "Angeeeeer! Equipment abuuuuse!" And you rapidly discover that these large inanimate bits of wood bite back if you hit them hard enough. At Rock in Rio, the first time we played it in '84, I was playing this nice guitar and the monitors just were not to my liking. It was only 500,000 people at the biggest rock gig in the world ever, we'd had three days of madness down there, proper Beatlemania, and we run onstage and I'm thinking: "Fucking hell, it sounds like shit!" I run over to the monitor desk and I'm yelling at the guy: "Your monitors suck, you cunt!" and I smashed the guitar in half over the top of his monitor desk to make the point, which didn't really solve anything. First of all I'd destroyed a perfectly good guitar, and the monitors were still shit. So I go back onstage in front of 500,000 people and kick the monitors off the front of the stage, so now there are no monitors. Worse than bad monitors is no monitors. We did the gig, apparently it was a classic. You do that when you're 18, 21, 22, but at some point you go: "This is all a bit self-important, isn't it? Is it all about me?"

FT: Has your voice changed with age?

BD: Yes, the tone of it changes because your body shape changes. As you get older your voice actually gets weightier, it gets fatter. [But with Maiden] there's only one singer, there's nobody hiding behind the amps, unlike some other guys we shan't mention. And we still don't have an Autocue. Yay! I never realised that people were using Autocues. What the fuck is that all about? People pay good money and you can't even remember the sodding words. The daftest one I ever saw was [Judas Priest's] Breaking the Law. It's on the fucking Autocue. "Breaking the law, breaking the law/Breaking the law, breaking the law/Breaking the law, breaking the law/Breaking the law" – guess what? – "breaking the law." It's ludicrous.

FT: We're on right before you guys at Sonisphere.

BD: Are you on before or after I get shot down? [The dogfight] only came about because we did the Spitfire [fly-past] last time for Download [in 2013]. My mate is the team manager for the Great War Display Team. They've all got replica first world war fighters. [My Fokker triplane] is Red Baron central. It flies exactly the same as the aeroplane did in 1917; it's like flying a giant set of bookshelves. We try to fill the sky with aeroplanes, so as you look up you'll see what looks like nine planes dogfighting each other and every now and then someone will catch fire and smoke will come out. What it looks like from the ground is one big sheet of aeroplanes all milling around. Any dogfighting actually takes place at 200 feet, front and centre in front of the audience. They said: "Do you have a parachute?" and I said: "What's the fucking point? At 200 feet, if you fuck it up you're dead."

FT: Then I'm onstage with an acoustic guitar!

Turner's well aware of what he's up against at Sonisphere. Out at Copenhell mixing desk he air-drums through the entire Maiden set as Dickinson leaps around the stage. But it's the punk rock freedom of Maiden and their fans that Turner really connects to. "There's something so dedicatedly anti-fashion about it," he says. "It's about music and community and it's completely impervious to outside suggestion. Maiden do Maiden and they don't give a fuck what anyone else thinks, and that's hugely inspiring to me."