Richard Dawkins is no stranger to controversy; musical and otherwise.

It’s hard to imagine, given how his recent remarks on the shooting of three Muslims in North Carolina have been taken, but the arguments against Dawkins were once quite mild. Back in 1995, after his appearance on Radio 4’s Desert Island Discs, the evolutionary biologist-turned-atheist campaigner was criticised for his choice of Bach’s St Matthew’s Passion — an odd choice, apparently, for such a vocal opponent of religion.

If such a small thing can draw discussion, his latest foray into the arts will presumably garner some fairly raised eyebrows — at least, if my inbox is anything to go by. When I message a friend to say I’m about to interview Richard Dawkins about Finnish metal, her response is simply “please explain this”.

It’s hard to know where to begin. It’s not every day, after all, you sit down to listen to a 24-minute symphonic metal track with rolling piano, cello and ape noises; and fewer still you get to watch a Scandinavian rockstar discussing childhood clarinet lessons with one of the country’s most prominent and – not to put too fine a point on it – most criticised public intellectuals.

When I meet Dawkins and Nightwish lyricist Tuomas — who is wearing a T-shirt with Charles Darwin’s face on — in a Kensington hotel, however, it seems a surprisingly straightforward collaboration. Both of them are disarmingly earnest about their work together; indeed, by the time I leave, it seems almost inevitable that Dawkins would be sampled on a Nightwish album.

For that is exactly what’s happened. A self-declared “life-long science fan”, Tuomas studied the subject at university before dropping out to pursue music. A recent interest in the works of Dawkins, as well as Christopher Hitchens, Carl Sagan and other figures, led to him approaching the scientist.

“I wrote him a handwritten letter, explaining what we had in mind”, says Tuomas. Two weeks later, Dawkins replied via e-mail expressing his willingness. They set up a studio date in Oxford, and less than six months later, two tracks are ready for the forthcoming album Endless Forms Most Beautiful.

Richard Dawkins recording in Oxford.

I ask Dawkins if he’d heard of Nightwish before he received Tuomas’ letter. There’s no sense of irony in his response.

“No, I hadn’t. But I was interested, I was intrigued and fascinated. I asked advice of my assistant, and he urged me to do it. I was pleased to do it.”

When I suggest that perhaps the genre is a little unexpected, Dawkins is sanguine. “Yes, it’s a bit of a different kind of music, but I am capable of being very moved by music.” The lyrics Tuomas has him read, alongside his own writing and the works of other scientists, are “beautiful”. When I ask if he'll play at Nightwish's upcoming Wembley show, both parties seem keen. "Let's do it."

Being moved by music is a topic Dawkins spoken on before. Is this an attempt to make the scientific sublime? “Exactly”, Dawkins says. “That’s so important.” Tuamos agrees: people may think of science and evolution as dry, but it’s “exact opposite of that. It’s the most poetic thing there is, evolution.”

And what of people who think Dawkins should stick to his discipline? “Yes, I can’t think what else I’ve done… I did that rather strange thing for Saatchi & Saatchi. A psychedelic extravagorama.”

Dawkins's performance at Saatchi & Saatchi.

It seems an easy thing to laugh at, but again, Dawkins seems to take it all at face value. His explanation of the “ewi” – which he plays at the end of the clip – is in-depth, conveying a genuine enthusiasm for the instrument.

I ask about other cultural gestures that have been awkwardly received in the press, like his recent Twitter poetry. “Did I do poetry?”

Darling let us wean a type Of mixture of us 2. Offer up your genotype & shuffle our codes anew Let me extend my phenotype Deep inside of you — Richard Dawkins (@RichardDawkins) March 5, 2014

“I call that comic verse. I don’t know why the Independent keeps picking up these ridiculous things.”

It’s impossible to tell if Dawkins is unaware how he is perceived, or just gifted with a total lack of self-doubt. Either way, it might explain something about his public persona. I ask if there’s a certain pleasure in provoking people – his detractors on the Christian right, for instance, will surely be unhappy that he’s now collaborating with a metal band. Dawkins seems not to know what I’m getting at. There’s a certain image, I suggest – “satanic?”, he fills in. Yes, perhaps.

And what about the Nightwish fans? According to Tuomas, “people are really excited”, but there is some opposition. He imitates some of his fan responses: “I’ve been a fan of Nightwish for fifteen years, I’ve seen twenty of your shows, but I will never ever come to see you again. I just burned all your CDs.”

“It’s good for publicity, that sort of thing”, says Dawkins. And he would know.

Endless Forms Most Beautiful is due out on 30 March. Nightwish – possibly featuring Richard Dawkins? – will headline Wembley Arena in December this year.