Three weeks before last Christmas, a shaggy jumble of an email flopped into my inbox. “Odd request,” it began. “Feel free to ignore if it makes no sense/is a load of old cobblers.”

It came from a publicist for Underworld. The electronic-music duo were “collating lists of things/people/places and then taking them into the studio to create music”, he wrote. Having seen The alternatives, my series of Guardian columns about how to make the economy work for everyone, he “wondered if there was a list of inspirational people/ideas/processes that could be easily scribbled down”. No windy sentences or long explanations, “just 10-20 things to act as triggers in the studio”.

Underworld! You know the name, even if all it brings back is that bit in Trainspotting when the soundtrack goes “Lager lager lager lager”. For me, however, Underworld means tramping around as a teenager with crumpled notes earned in a Saturday job searching out their earliest 12-inches. It means some of the most splendid and determinedly wayward British music to be labelled techno. So, the email was off the wall, and music people can be flakier than a 99 cone, but I thought: where is the harm in jotting down a few random phrases and bunging them off into the ether?

It took about 10 minutes: typed, emailed, laptop closed. Then all was forgotten in the pell-mell of Brexmas.

Scroll forward to a honeyed morning in the middle of last week. I am deep in the bit of north Essex that minds its consonants and pretends it is Cambridge, down a dirt track in a converted pig shed surrounded by fields. This complex of former farm outhouses is Underworld HQ, with rooms devoted to old equipment, records and what looks like an entire wall of coiled cables. Sitting on either side of me around a long, black table, Rick Smith and Karl Hyde explain what happened when they received my reply.

Watch the video for Soniamode (Aditya Game Version).

The Observer has dubbed them “electronic heroes”, but the pair who live in this rolling countryside display relaxed courtesy. (They didn’t instigate this interview – I suggested it.) Even with his bleached-blond hair and zesty-green shirt, Hyde – the singer – gives only flashes of his onstage puckishness. Smith – the producer – is tall and crowned with grey, looking like the encouraging headmaster of an Anglican primary.

Out of Smith’s laptop surges a bassline, the signature that announces: “Hello! We are Underworld,” even to people who haven’t checked in on them for two decades. He points out each part as it comes in: modular synths, electronic drums, whistles, snatches of jazz piano and “tiny samples of Karl’s voice, which he chopped up himself”. The song, Soniamode, builds into what he calls “a nuts techno New Orleans street band”, overloaded machines seething and restless. On his laptop, he shows a close-up photo of a giant synth, thick cables jammed into its array of holes. “That is Soniamode.”

This was the track as it stood a few months before; now it has extra vocals. When Underworld emerged in the early 90s, dance music either ignored words completely or chose large-lunged positivity. “Peace in the Valley!” declared singers who had obviously never visited Kashmir. What made Hyde so unusual was how cut-up and overheard his lyrics were, like David Bowie sitting at the back of a night bus.

Lately, he and Smith have been studying the sticky magic of nursery rhymes, how they spread from place to place and generation to generation. On this track, they try their own version: “Boogie front / Toy toy / Boogie back / Toy toy.” Then, around the halfway mark, everything swings a sharp left: Hyde announces “the hopeful ideas for the future game” and, in his faint Midlands twang, starts shouting phrases that I last saw in an email five months earlier. “Workers’ co-ops ... maker spaces ... guerrilla localism ...”

Jotting down my pre-Christmas list, I mentioned no people, but four inspiring places: Witney, because of its community-run bus service; Granby, in Liverpool, for its resident-directed housing; Rochdale, the birthplace of England’s co-operative movement; and Preston, where the city council is breaking with a failed economic system. This becomes the chorus: “Witney, Granby, Rochdale, Preston.” Over and over runs the loop. Witney, Granby, Rochdale, Preston.

Rick Smith (left) and Karl Hyde. Their Drift programme of weekly releases ‘grew out of boredom’, Hyde says. Photograph: Alecsandra Raluca Dragoi/The Guardian

Thanks to this listening exercise, I can report that the universal strangeness of hearing yourself on tape pales next to the absurdity of your words being sung by the voice that soundtracked stretches of your life. Hyde used to bring to my headphones tales from “the midnight train to Romford”; now he is crooning about employee ownership of businesses. I can’t decide whether this is the high point of my hegemonic ambitions or an out-of-body experience.

I wonder, too, if anything approaching this species of bizarreness has befallen other newspaper columnists. Has the Times man Lord Finkelstein submitted the odd verse for Stormzy? Did the Sunday Telegraph doyenne Janet Daley ever chip in the occasional line for Adele? Could whoever among the Economist’s precocious 12-year-olds now writes the Bagehot’s notebook column have helped out Little Mix? I think not.

Yet this track today becomes a single that will follow music-industry tradition in being played – exclusively – by BBC Radio 6 Music’s champion of off-kilter dance music, Mary Anne Hobbs. It has artwork and a name: Soniamode (Aditya Game Version). It is, in other words, an artefact, just like my 12-inches that, thanks to the arrival of my baby girl, have been Marie Kondoed away.

Finished two weeks ago, the single is being released alongside Underworld’s Drift programme of releasing a piece of music and a film every Thursday for a year. They have been making music together for four decades and now they want to shake the bottle and wake the drink – to work fast and seek out what Smith says are “the collaborations and chance encounters that are fundamental to every artist”.

“It grew out of boredom,” says Hyde. “Boredom with the old cycle of lead track/single/album/tour and then, three years later, lead track/single/album – with a three-week window for publicity. Like: what?” Putting the charts and fans’ expectations out of mind, they are attempting a kind of musical mindfulness. “‘What are you listening to?’ ‘What did you see on your walk?’ That’s as viable as a big kick drum, if you follow your heart.”

Smith chimes in: “Whether it’s good or bad, we’ll record with more honesty in this one year than we have in the previous 15,” which is to say since just after they released the single Two Months Off. “I mean, COME ON!” His arms shoot up, as if he has just scored a free kick. “We’ve got to try that.”

Around the time I fired off my email, the pair were getting lots of lists. “Best books I’ve read in the past year”, “Places that were dear to me that are now closed”, that kind of thing. “Those were doable,” says Hyde. “Move a few of the words around and you can get a groove going. You know Born Slippy?”

I believe it was a smash-hit single, m’lud.

“Well, why did I go “Lager lager lager lager”? Because I lost my place on the page, so kept repeating the same word. But your list was just: ‘Oh, Jesus,’ so that was the one to start with.”

Smith, on the other hand, wanted to work out what on earth I was on about. “What is it about Preston? Why Granby? What are ‘corporate welfare queens’?” What should have been a writing session in the studio turned into a reading marathon. “I went through years of your work, especially The alternatives. ‘Oh my goodness! These people have done that.’”

Why did I go 'Lager lager lager lager'? Because I lost my place on the page

There is one big thing Underworld share with many of the people I wrote about for The alternatives: they are ahead of their peers and slightly out of step with them. In a music industry that is overwhelmingly metropolitan and middle class, their origins are small-town working class. Brought up in Ammanford, half an hour’s drive from Swansea, Smith worked previously as a bank clerk in Llanelli. His dad was a toolmaker, a salesman and a lay pastor, while his mum taught piano. Hyde was brought up in Bewdley, Worcestershire. His dad worked in a carpet factory in nearby Kidderminster, where his mum ran a dry cleaners’ shop.

The pair met as students in Cardiff while working in a burger bar. The music they made for the next decade was more about trying to tickle the charts than channelling Kraftwerk, Neu! and the other German bands they loved. Their reward was to be dropped by their record label. It was then that they started making their oddly charismatic electronic music, but they remained determinedly marginal, dropping anchor not in London but in Romford, Essex, and refusing to pump out endless remakes of Born Slippy. As an Essex cabbie once lamented to Hyde, they could have been the Prodigy; part of their magic is that they stubbornly preferred to remain Underworld.

In the past few years, they have started campaigning about homelessness. They launched Manchester Street Poem, a soundtracked installation telling the stories of local homeless people, at the Manchester international festival in 2017. It is an award-winning project with which Hyde, in particular, remains involved.

“It’s about community. Some of our colleagues, who are former rough sleepers, said: just stop and talk,” he says. “So we asked: do you know who that is? That’s Sandra and that’s Kevin – and did you know Kevin used to be a bank manager and Sandra had children who were taken off her? And the number of people who get in touch and say: ‘That could have been me.’”

Hyde thinks stories of community organising should be on the news, “but what we get instead is that we’d better be really scared and blame Them. Who’s Them? Anybody but me. My father reads a particular paper that fills him with a particular opinion.”

Underworld performing in Manchester in July 2016. Photograph: Andrew Benge/Redferns

Is it the Daily Mail?

“Hmm.”

(It is clearly the Mail.)

“He used to buy it and I’d say: ‘Don’t leave it for my kids to see, please.’ I’d rather he left porn.”

But you two came through the rave scene, I say, with all its legends of football hooligans setting aside their blood feuds and getting on one: didn’t that movement promise we would all come together?

“These people didn’t beat each other up and girls weren’t getting hit on and the cultural differences went out of the window,” concedes Hyde.

But those were also days of poverty. “I remember that feeling of being one pay cheque away from homelessness,” Smith says. “Wanting to look after my family, desperately needing to earn money.” They would borrow £600 to print up some records that Smith would stick in the back of his mother-in-law’s Ford Fiesta and try to flog to record shops in Soho.

Decades later, they have done everything: played up mountains and in castles, jammed for 15 hours straight in a field at Glastonbury, scored films and gold discs. They have two children each. Smith is about to enter his seventh decade, while Hyde turned 62 a few days ago. “We were in the Yorkshire Dales at the weekend, doing the Three Peaks Challenge, and as I was coming down the second hill I felt something go and said: ‘I won’t do the third, thank you very much.’”

Over Underworld’s 40 years together, the music industry has gone from vinyl to MP3, from labels sustaining a wide range of artists by means of intricate cross-subsidy to billions for the likes of Ed Sheeran and Taylor Swift and pennies for the rest. It is a place that has less space and attention, even for bands of Underworld’s stature. Where do they see themselves in today’s industry? “In this pig shed, under a beautiful sky,” says Hyde. They are constructing an alternative with their collaborators: Malcolm the studio boss, Mike the manager and Robin the publicist.

Then Alecsandra, the Guardian’s photographer, starts taking pictures – and these thoughtful, self-questioning men suddenly turn into the band. Firing up his giant mixing desk, Smith begins improvising a version of Soniamode, hitting buttons marked Zombie Economics, Zombie Government and Addictive Drums. Bouncing around, Hyde puts on a falsetto: “Drop the kick drum, Rick, you’re so great!”

Smith obliges, to acclaim from helium Hyde: “He really is the god of techno! He walks among us.”

Then Smith starts looping my words over the Underworld classic Cowgirl, which suddenly I remember playing on my broken Sony midi hi-fi. “Oy-yoy-yoy-yoy,” sings Hyde absent-mindedly, as if down the local where an old favourite has just come on. How does he feel when he performs this now? A big grin. “Very often, I feel grateful still to be alive.”

Soniamode (Aditya Game Version) by Underworld is released on 21 May. It can be streamed on various platforms here. Underworld play the Sydney Opera House at Vivid Sydney on 31 May-3 June; and Wembley Arena, London, on 7 December