When the Cornish started emigrating to Australia in the mid-1800s, their mining skills were highly sought after. Their singing skills, however, were not always as valued. “Carolling was so popular that it was almost a nuisance,” says Cornwall-born ethnomusicologist Kate Neale. “One historic newspaper said, ‘The town was overrun with carollers, good, bad and indifferent.’ They weren’t always welcome, depending on the quality of the singers. But we’re not in the situation any more where you could be overrun with carollers – just getting them performed at all is fantastic.”

On the last Thursday before Christmas, the cobbled streets of Truro aren’t overrun by anyone and could really do with some rowdy singers to disturb the eerie quiet. But the unusual three-spired cathedral is packed with locals (and one Australian visitor who made the trip especially) here to listen to the carols of the Cornish diaspora that Neale has been researching for her PhD. Between 1861 and 1901, an estimated 250,000 Cornish people moved to Australia and New Zealand, the Americas and South Africa following the decline of the copper and tin industries that had made Cornwall a world leader in mining. These “Cousin Jacks” took their traditions with them and embedded them in their new homes, where many of their ancestors endure today.

Neale, arts facilitator Emma Mansfield and historian Hilary Coleman have convened three new choirs from across the county to sing, respectively, the grassroots carols that remained in Cornwall, those that travelled to Grass Valley, California, and those written by Cornish migrants after they moved to the Copper Triangle towns of Kadina, Moonta and Wallaroo in South Australia. They’re unlikely ever to have been performed anywhere as auspicious as Truro Cathedral, says Neale, and not just because they come from a Methodist tradition. “They would have been sung, as the common phrase goes, in pubs and chapels and highways and hedges,” she says. “It’s not highbrow, it’s not even seen as accomplished or valuable art, but it is emotionally and culturally very valuable.”

The Cornish carols may have humble origins in mining, fishing and farming, but they hew to the complex, archaic fuguing psalmody, comprising four-part harmonies and canons: “These lovely ripples and cascades of music really reflect the breadth of voices at that time,” says Mansfield. Often, the lyrics themselves concern singing: “High let us swell our tuneful notes / And join the angelic throng,” goes one carol by James Leslie Davey, who settled in Australia. “These songs are really about rejoicing, sharing the voice, praising, ‘hark the glad sound’,” says Mansfield. “They’re really positive. You can’t fail to come out of rehearsals feeling on a higher plane of vibration.”

Plans for the concert started in September 2017 when Mansfield spoke with intrepid independent councillor Bert Biscoe, who talked the Very Rev Roger Bush, dean of Truro, into the idea. Funding from Arts Council England and local bodies enabled Mansfield to get the obscure scores retranscribed to make the music as accessible for local singers, who were recruited through Facebook and local media and span age 18 to 80-odd. “I did not know what to expect, but we nailed a song a week,” says Mansfield. “I was so impressed. You could see everybody going, ‘Did we really do that?’”

Neale suggests that Cornwall has a weaker relationship with these songs today than the communities in Australia and California. In the 1940s, Grass Valley’s miners sang carols from down the goldmines in radio broadcasts heard nationwide. The male choirs disbanded in the 60s after the mines closed, but were revived (and welcomed allcomers) in the 1990s. Every Thursday between Thanksgiving and Christmas, locals hold a Victoriana event called Cornish Christmas. “The carol choir perform on the steps of the building where the previous choir would have done the same,” says Neale. In Moonta, locals claim that the national tradition of singing carols in candlelit parks on December summer nights started with 19th-century Cornish miners singing in the copper mines.

Cornwall, Neale says, “has sometimes struggled with its cultural identity: depending on your perspective it could be anything from an English county to a Celtic nation and lots of different things in between”. Many of her newly minted carollers had never heard of the house-visiting tradition, but asked why they shouldn’t carry it on. “It’s not been my aim through my research to be a cultural activist, but to see that there is interest and enjoyment in the music is wonderful,” she says. Citing Welsh Cornish-language singer Gwenno and local comedian and playwright Kernow King (AKA Edward Rowe), she’s hopeful about renewed interest in Cornish culture. “Maybe it’s a slow grind into not being seen as a petty nationalist fight for identity, that there is something deeper and emotionally held there for a lot of people.”

There are wider resonances, too: the intertwining of the traditional Christmas migration story with that of the Cornish people who weren’t just seeking employment but often fleeing religious oppression. Cornwall voted for Brexit and has isolationist tendencies, something Roger Bush seems to warn against in his address about the importance of welcoming the “lowly and the outsider” and their establishing community. “The song is the essence of who we are,” the dean tells the congregation, a sentiment Mansfield echoes. She established a choir in Lostwithiel after having a nervous breakdown 11 years ago, and runs a singing festival called Sing Along the River. “I’ve seen extraordinary evidence of how coming together in a singing group can build communities and heal people.”

What the Cornish carols lack in traditional festive familiarity the sight of the choirs more than makes up for. The singers are dressed smartly in black with flashes of yellow and Cornish tartan. The male bass singers of the west Cornwall choir, singing the grassroots songs, produce resonances that seem to reach deep down into the county’s dormant mining shafts, though they’re matched by some equally formidable women bassists in the east Cornwall group, singing the Australian songs. And at Thursday’s Cornish Christmas in California, the Grass Valley choir sang the same jubilant carols as the mid-Cornwall choir did in Truro.

Set against the cathedral’s old and beloved nativity scene, awaiting the installation of the Christ figure on Christmas day, it feels as though an annual tradition is being reborn. “I’ve come out of this project thinking we need to write our own carols, from our time,” says Mansfield. “Work with the Cornish writers and poets and musicians and create a whole new body of work.”