YORKSHIRE folk duo O'Hooley & Tidow are on tour promoting their July album Shadows, playing the National Centre for Early Music in York tomorrow night.

"We've played there before, about two years since, for The Hum album that came out in February 2014," recalls Heidi Tidow (pronounced tee-dough), one half of the Colne Valley combo with Belinda O'Hooley.

The groundbreaking The Hum brought O'Hooley & Tidow a place in Mojo magazine's Top Ten Folk Albums of 2014, a nomination for Best Duo in last year’s BBC Radio 2 Folk Awards, a Top of the World album selection in Songlines magazine, a five-star live review and feature in The Guardian and an invitation from Billy Bragg to perform at Glastonbury.

A hard act to follow, in other words. "When we brought out The Hum we felt it was the best thing we had done. It took us a long time to write and we kind of felt, 'where do we go from here?', which was a bit intimidating, but from there we took a little detour, called Summat's Brewing, an album of drinking songs that we recorded, produced and self-released on our label Hum Records."

Summat's Brewing celebrated the "spirit of the small" while exploring the nation's fascination with alcohol. "We played 30 pubs and microbreweries, all for research purposes of course! You have to suffer for your art! It took us to the heart of the pub scene and the live music scene as we switched our focus for a while and then got our heads down to make Shadows."

The resulting album "conveys the vast expanse of human emotion, from tenderness to sensual melancholy, boundless joy and hope to anger and grief, from dogged determination and grit to the disturbing and deeply unsettling".

Shadows both considers those who live their lives in the dark and others who are gently lifted out of the dusk, from Belinda and Heidi’s deeply personal shadows, to the crimes committed behind closed doors.

"We feel the songs are stronger, the arrangements are stronger, after playing so much in the last two years. There's nothing like playing live to work on your craft," says Heidi.

"For the songs, we tend to get an idea, do the research, brain-storm it and it seems the melodies tend to come out of that work. When we then put the record together, we consider all the aspects, the sleeve notes, the artwork, the range of topics and styles, the song order."

Subject matter on Shadows ranges from the Colne Valley's eccentric characters (Colne Valley Hearts) to orphaned elephants (Blanket); contradictions embodied by UKIP and the BNP (Made In England) to child abuse lurking behind the cloak of religion in Reapers. "We're both Catholics, but not practising as you can tell from the song," says Heidi. "We wanted to be able to give a voice to the children...and no, we haven't had a reaction to the song from the Church."

O'Hooley & Tidow play National Centre for Early Music, York, tomorrow, supported by Duncan McFarlane at 7.30pm. Box office: 01904 658338 or at ncem.co.uk