Folk music and The Unthanks fans should head for RNCM’s ghoulish gig.

“Murdered lovers, kisses that kill” and otherworldly voices to die for – that’s the sort of stuff you need for a good old midwinter’s night out, isn’t it? Well, that’s the premise of Crows’ Bones, a specially curated evening for Opera North of “folk songs about ghosts, ghouls and unquiet spirits” at RNCM this week. It’s led by Martin Green, accordionist with the award-winning folk adventurers Lau, along with a collection of folk luminaries including The Unthanks’ Becky Unthank, singer Inge Thomson from Karine Polwart’s band and nykelharpist Niklas Roswall. “I’ve always been interested in these sorts of songs,” says Green, “and I’d done some work with Opera North who, I’ve been pleased to discover, have a very broad idea of what they can put on as ‘opera’.”

It’s essentially like a spooky gig, albeit one linked by storytellers, some living, some dead, and some neither

“When Opera North commissioned me back in May, my first thought was about the sound of the show, says Green. “Fans of The Unthanks (‘known as we are for the darker, more melancholy, side of the tradition,’ says Becky Unthank) and anyone who has heard Inge singing with Karine Polwart will know that they both have something of an ethereal, otherworldly quality to their voices. So it seemed obvious to me that they should be involved, not least as they managed to find time in their own diaries. But what surprised me is the way that they can sound together. The number of more modern songs they managed to find was also unexpected, I admit, but just goes to show that these sorts of stories aren’t a passing fad.”

The evening begins with a chance to hear Roswall play a set of traditional Scandinavian tunes and midwinter songs before he joins the group. “The sound of the nykelharp, although it’s a relatively modern instrument in the form we know it, has a sort of timeless quality that makes it absolutely right for this sort of evening,” says Green. And what sort of evening will it be? “Although it’s under the banner of Opera North, there isn’t really a narrative to it,” he says. “But there is a theatricality inherent in the songs that we’ve tried to emphasise with the staging and with Ben Everett’s lighting design. It’s essentially like a spooky gig, I suppose, albeit one linked by storytellers who are, as we like to say, ‘some living, some dead, and some neither’.