The Unthanks with Brighouse and Rastrick Brass Band, York Minster, August 17

THE journey began in Durham Cathedral and ends at York Minster next Friday. Perfect symmetry for The Unthanks, the folk group that combines north-eastern singing sisters Rachel and Becky Unthank with Yorkshire pianist, composer and producer Adrian McNally.

“Playing York Minster means that we have matching bookends to this project with the Brighouse and Rastrick Brass Band, after starting in Durham in July last year,” says Adrian.

They will be performing once more with the brass world’s National Champions Of Great Britain, a partnership that came together when Brass – Durham International Festival commissioned The Unthanks to write a piece for last year’s festival.

As chance would have it, Adrian’s invitation from “probably the most important brass festival in the UK” to write his first large-scale scores coincided with the imminent arrival of his and Rachel’s first child.

And so a child was born and The Father’s Suite was spawned. “The concert was just four weeks after the birth of our son, George, who arrived a little late,” recalls Adrian.

“With four weeks to go, Rachel hadn’t given birth and I hadn’t written a note as we’d come straight out of the tour for our album Last, when Rachel was still performing when she was eight months pregnant.”

The idea for Father’s Suite, the centrepiece of The Unthanks’ concert and album collaboration with the Brighouse musicians, had in truth come to Adrian a little earlier than when he was able to focus fully on the commission. “I did actually use as a basis for the first movement the first thing I came up with on the piano as a boy, when I was 14 or 15,” he says.

“It was something that stayed in my head and I’ve knocked around with it for most of my life and if you’d told my 15-year-old self that it would be played back to me by a brass band all these years later… I wouldn’t have believed it.

“Nor would my father believe it, as the last piece in the suite was something that he wrote, and though I’d never tried to play it myself I didn’t need to consult him as I’d consigned it to my memory.”

Adrian has had no formal training and is unable to read or write music, but with the assistance of Unthanks fiddle player Niopha Keegan he has written brass scores for half the songs that feature on the new Diversions Vol 2 album on RabbleRouser Music.

As with the series of concerts, the other half comprises songs that have appeared on previous Unthanks albums, now adapted for brass by conductor Sandy Smith.

“It’s been awesome to play with the Brighouse band; we feel so lucky to doing that and we’ve had such generosity in the writing process, with the conductors being so patient with our writing abilities,” says Adrian.

Writing for brass has been an amazing challenge, says Adrian. “To get the balance right, because of the power of brass band music, was crucial, but I was never in doubt I would get it right, given that for me, brass music is at its most beautiful when it’s at its most restrained.

“It’s like a giant: when a giant is gentle, it’s all the more impressive, and when you do let it off the leash, the power is all the more impressive for having shown restraint.

“My love of brass is as much from Miles Davis’s music on A Kind Of Blue as from brass band music and the tenderness of that is something I’ve grown up with.”

This, however, tells only part of the story. The prospect of performing music steeped in the mining tradition in Yorkshire’s mother church hits home for Adrian.

“Having grown up between Barnsley and Wakefield, in South Hiendley, a couple of miles from Grimethorpe Colliery, home of the most famous colliery band in the world, mining and brass bands are in my DNA,” he says.

“Rachel and Becky grew up in the Gateshead, Tyne valley area, which was once full of pits, and in the village where I grew up in 1982/83 it had four sweet shops, four pubs, a hairdressers, a fish and chip shop, and it was quite a bustling place. I was 11 when everything changed in the pit closures of 1984; within a year it had all gone.

“I can remember, as a Barnsley fan, the attendance at Oakwell went down from 16,000 to 5,000. Though my father wasn’t a miner, my grandfather was, and even now these places are still trying to recover and to some extent are like ghost towns.”

Reflecting on that past has been emotive for Adrian. “I wouldn’t say we’re a political band or a protest band as we prefer to engage with human empathy rather than through anger, but I think any form of political engagement is positive,” he says. “The stories we tend to draw on are more unifying than they are divisive.”

That, of course, is the power of music, be it brass bands or The Unthanks’ next volume of their Diversions series: Songs From The Shipyards in the autumn.

• The Unthanks with Brighouse and Rastrick Brass Band, York Minster, August 17, 8pm. Ticket update: selling out rapidly on 0844 939 0015.