Above Fala Moor today, the birdless sky burns blue. As we walk, the ice crackles beneath our feet and the wind hums the morning's soundtrack.

You will often find Karine Polwart here. This flat expanse of peat and moss some 1,200ft above sea level is where the folk singer, mother, teenage Aberdeen FC fan, and resident of this area for the last eight years, comes when she has time. "I love it. I get totally restored when I go for a walk here."

Restored and inspired. We are here walking and talking to cover the ground – both literally and figuratively – of her most ambitious work yet. Formerly a singer with Malinky and the Battlefield Band and then an award-winning solo singer whose work sums up the worst and best of us in the most beautiful way (the music critic Graeme Thomson once said she "makes soul music for a nation raised on Calvinism") Polwart has been spreading her wings.

Last year her show Wind Resistance – a performance piece encompassing music and spoken word – was one of the highlights of the Edinburgh International Festival. Next month she will breathe new life into it at Celtic Connections.

The show represents something of a new beginning for Polwart. There have been a few of them of late, in life and work. And we're here to retrace her steps. To find an origin story if you like, for Wind Resistance and perhaps for Polwart herself.

The former first. Every year some 2,500 pink-footed geese fly from Iceland and Greenland to nest on this moor in Midlothian for the winter. One day seeing them in the air Polwart asked herself a simple question. Why do they fly like that? One Google search later she had her answer. And the inspiration for Wind Resistance.

"I discovered that this whole skein flight formation is this amazing aerodynamic sanctuary," she explains as we walk.

"You can see it when you watch the sky. The birds move up to the front and then they fall back. Every bird takes a turn. The bird at the front cuts the drag of the bird behind by up to two-thirds. It's this amazing kind of co-operative form of flying all the way from Iceland and Greenland, through all the crazy winds of the north, to come to Fala every winter.

"And the only way to do that is as a single co-operative unit where everybody takes responsibility at some point and everybody takes a rest.

"And I thought," she continues, "'how do we do that as people? What's the analogous form of co-operation for us?'"

And that's when she remembered the huge medieval hospital that used to sit on this very landscape, the largest north of York, run by Augustinian monks for centuries from the 12th century.

"The whole idea of sanctuary began to pop up. It's written into the land."

Into her own life too. Ideas of refuge and healing. The Augustinian monks did midwifery (although forbidden to do so) on a rise above the moor. The archaeological evidence says as much. Not so very far away and not quite so long ago Polwart gave birth to her son at the Borders General Hospital. Eventually.

"My son got stuck. It was technically what's called a compound presentation birth. He got stuck coming out. It was the kind of birth that if you didn't have access to midwifery care it would kill you and your child."

Talking to friends and family she would hear stories of epidurals, pre-eclampsia, forceps deliveries. "I have known people who have died in childbirth in my generation."

All of this – the land, the history, personal experience, song and spoken word and even Aberdeen's European Cup-winner's Cup victory in 1983 (Sir Alex Ferguson, she tells me, used the example of the goose skein in team talks. So much so, that Ronaldo and Ryan Giggs would stop training to look at birds in the sky) come together in I Wind Resistance. It is folk theatre as politics.

"Politically to me that's the big issue of our times. The incremental erosion of the idea of collectivism and the idea of universal care. Our NHS is under threat. Our welfare system is being consistently eroded. I see our NHS to have evolved out of what the Augustinian monks did 800 years ago. 800 years of evolution gets us to the point of universal care. What happens if you start to take that back?"

"What I worry about," she adds later, "is losing the sense of 'we-ness' and getting into little pockets of individual isolation.

"So Wind Resistance is my own little form of rally, saying 'we need each other.' Your lone goose trying to fly from Iceland is toast. It's not going to make it. So could we just think of ourselves a little more like geese?"

Working with the likes of dramaturge David Greig and sound designer Pippa Murphy, Wind Resistance is a big step up in ambition for Polwart. Could she have imagined doing something of this scale 20 years ago?

"20 years ago I couldn't even have imagined being a musician, never mind doing an international festival show."

Born at the tail end of 1970, Karine Polwart grew up on the edge of the Stirlingshire village of Banknock, the countryside to her back and out front "wall to wall small town all the way to Grangemouth."

Her route to music was slightly circuitous. She wanted to be a musician as a teenager but was discouraged from pursuing it at school and instead studied politics, history and philosophy at university. She loved it, still loves "geeking out in the archives". (Wind Resistance, she says, was good for that, she says.)

After uni she taught philosophical enquiry in schools in Glasgow. "Taught is maybe not the right word," she clarifies. "Facilitated philosophical discussion among kids in community settings. And in truth I would be doing that now, but the funding ran out."

She ended up working for Scottish Women's Aid. "It was highly politicised work," she admits, "and it was during the time I worked there that I got really into folk music and particularly traditional music.

"One of my Stirlingshire compadres Aidan Moffat has in the past year in the film with Sheila Stewart [Where You're Meant To Be, in which the former Arab Strapper clashed with Stewart over their ideas of folk music] asked the question 'how do you make these traditional songs relevant?' I've never felt any doubt about their relevance.

"When I discovered traditional song a bit of me was going 'oh my God, I can't believe there's a 400-year-old song about domestic violence'. I never felt I need to update those things. For me the resonance was just there. It was literally when I was working in the field of domestic abuse when I realised that tons of ballads were essentially about domestic abuse or cruelty to women. There's a continuum of human experience here."

Sad and upsetting human experience, often. Did her job with Scottish Women’s Aid ever leave her despairing? No, she says, because you would meet women and children of “unbelievable resilience”.

It became much harder when she moved into policy-based areas. “When I was working directly with people the evidence was there on a daily basis that they can sustain themselves through horrendous circumstances. That’s very encouraging paradoxically.

“I found it much more difficult to work in a paper environment and that was what ultimately fuelled my decision to leave. I just felt mired in organisational politics and bureaucracy and paper and had lost the connection.”

Still, it was a big decision to leave it behind for music. She has said in the past it entailed a sense of guilt. “You work for a cause and you can pin yourself to that cause and it justifies your existence,” she agrees now. But that was then. “I don’t feel that at all anymore.”

And anyway, in a way, she never stopped being engaged with the issues that she encountered while working at Women’s Aid.

“I always had things to say, even within the context of Malinky. The stories I chose to tell were mostly about women. Most of the songs I wrote were about cruelty to women almost exclusively. They were post-Women’s Aid songs. They all feel like different ways of poking away at the same stuff and now this step into theatre feels like another widening of parameters.”

She went solo in 2004 and she’s been a fixture on the folk scene since. There has also been a life lived. She is now the mother of two children.

In 2014, just before the referendum vote, she wrote an eloquent essay for The Sunday Herald which opened with the following line: “The Scottish independence referendum process has coincided almost exactly with the amicable, intentional but disorientating break-up of my marriage.”

The essay went on to map the experience onto the country’s ongoing questions about its future. The personal is the political of course. What I want to ask her two years on is how separation has changed her sense of self. Is she a different person now?

“I guess I feel I am. Oddly, right now I’m a 50 per cent carer for my children. So, 50 per cent of the time I’m a lone parent and 50 per cent of the time I have no immediate caring responsibility. They’re quite polarised ways of being. It takes a lot of effort to manage that extreme of contrasts.

“But it means that I feel very strongly I’m a better parent than I was before because when I’m there I’m really there and I’m centred and I’m calm and I’m not squashed by life.

“And I’ve this other part of my life where I’m able to be unbelievably free in what I do in terms of what I’m able to make.”

She gestures to the moor around us. “I’m able to come for a walk and not to have to ask permission constantly.”

It has asked questions of her, and of her family. “Working out what it is to be resilient on my own terms. Yeah, lots of questions come up around what it is to be a family,” she says.

“I’m very fortunate to get on very well with my kids’ dad. We live in the same area. But you have to start again with the whole idea of what it is to co-operate and share care of something.

“That stuff has been up in the air for me in a way that feels quite healthy because I think there can be an isolation bout being caught in little units as well and what it’s forced me to realise is I need the support of many other people.”

Literally so when she moved out of the family home. “I couldn’t have sustained myself over the past few years without the help of half a dozen pals who’ve literally been there. Emotional stuff and practical support, enabling me to work, giving me a place to stay, cooking my dinner. All that kind of stuff. If you’re fortunate and you’ve got these networks of resilience things that people do for you when you’re in crisis mode. My resilience is these people. I’m not an isolated individual. I need all these other people.”

It’s as simple and profound as that and it’s what we humans do at our best. A few days after we speak she is performing at a concert for Dick Gaughan, who suffered a suspected stroke and cannot support himself. It’s wonderful that people will come together to help out a fellow performer who is ill and needs their aid, she says. But it’s also terrible that he should have to ask his fellow musicians for that aid.

We are the sum of the ties that bind us.

Her change in personal circumstances have impacted on her working life too inevitably. “I used to do 20-25 date tours twice a year. Impossible. Just not going to happen. So, there’s this whole question of how is it possible to sustain myself as a working musician and writer.”

It has become more difficult as income streams in music are now so based around the live experience. “I need to find some other ways to make projects happen. It’s about creating projects that work around the way my life is and not me jumping through hoops to accommodate somebody else’s idea of how things should be. And that’s still total work-in-progress stuff.

It is not a world designed for people with caring responsibilities, she says, “which means it’s not a world that’s designed for a lot of women because those caring responsibilities still fall disproportionately on women. And it’s a big issue for lots of women musicians.

“It’s forced me to think about other ways of making work.”

Wind Resistance is one result of that. She wants to take the ideas she has explored in it further. There are plans for a CD, maybe a book. And the experience has already changed gigs. She has started inserting spoken-word pieces into her shows. “And people have responded really beautifully to that. As long as I’m still performing and writing songs I feel like I’ve got a lot of licence to muck about and I’m taking risks now.”

An hour has passed, an hour out in the world. We haven’t seen any geese but we’ve followed their flight path through history and Polwart’s own life story. We turn for home. What does that word mean to Polwart now?

“For me there has been a literal need to be at home in my house, in my street, to create work I can do on my kitchen table. I wanted to feel a much stronger connection to the literal geographic community that I live in which is in large part why I wanted to explore this landscape because it’s here and it’s as relevant and rich and as full of stories as any landscape.”

Leave it there. We are the stories we tell. Karine Polwart knows that. She always has.

Karine Polwart will perform Wind Resistance at the Tron Theatre from January 25 to January 28 as part of Celtic Connections. For more information and to book tickets visit celticconnections.com