Rising UK soul-folk star Josephine Oniyama may be well-versed in the American songbook, but her heart and guitars belong to Manchester.

"I used to listen to a lot of American folk music when I was growing up – Odetta, Johnny Cash, Bob Dylan," says Oniyama, who records under the mononym Josephine. Her current album, Portrait, looks set to win her legions of fans in the vein of Adele, Florence and Emeli Sande – and her versatile, dynamic voice recalls US greats like blues-rock firebrand Grace Slick and "Queen of Gospel" Mahalia Jackson – but her ethos reflects her native city, a bygone hotbed of Northern Soul.

"Manchester had a massive impact on my music," says the singer-songwriter. "I picked up a guitar at school because there's such a local history of guitar bands like Oasis and The Smiths, and I've gigged since I was 15 ,which is a real Manchester thing. No matter how young you are, or how rubbish you are," she laughs "you can always find a gig."

Almost 15 years since those nascent performances, Oniyama has released a classic album in Portrait, but that's only part of the story. Ten years ago she released a debut LP, the now-poignantly titled A Smaller Version of the Real Thing, and there was also a brief dalliance with Island Records circa 2008 for The Labyrinth EP. If these experiences laid down the foundations for Portrait's formidable entrance, they were reinforced by Leo Abrahams, who produced and co-wrote the new record.

"Leo really wanted to keep the folk element in my songs," Oniyama recalls. "He was adamant about keeping those structures, and he was great at playing to the songs. He separated out all my different styles, but somehow kept them cohesive."

Portrait's vintage blend of guitar-gospel, soul-folk and blues-pop is variegated yet consistent, from the gorgeous urban psalm of When We Were Trespassers to the societal snapshot of torch-song (and forthcoming single) Portrait. Many of Oniyama's American folk heroes were concerned with art-as-political-conduit: is there a social imperative in her own work?

"I think most musicians feel that obligation to comment on things, but it's a question of how much you can be a social commentator without losing people's attention," she offers. "You've got to be subtle about it. I think Portrait is the biggest social comment I've got on the album, without being overbearing. It's about what do we do in our lives that disguises us – at the moment, there's lots of technology, social media, TV, all these different influences, making us different from how we should be."

As a single and an album title, Portrait also provides a theme of (self) reflection that is mirrored throughout the LP, from the upbeat guitar-groove of A Freak A ("If you have a mask, get it out and put it on"), through the delirious chamber-rock of What A Day ("Are you seeing right through me?"), to sepia piano-ballad House of Mirrors ("I try to find familiar faces"). Are these myriad references to facades designed to make us take a look at ourselves?

"I'd never realised the connection, to be honest – I think you're on to something there," she says. "I guess a lot of the record is about trying to be yourself – that's definitely what A Freak A, and Portrait, are about, in a general sense. House of Mirrors is a bit more personal and a lot more specific because at that point I was doing a lot of different writing sessions, travelling all over, working in Manchester, just living all these different kinds of lives. And I just thought, 'What am I doing here?' That's really reflected in House of Mirrors. It's me looking at myself."

Given Josephine's recent TV appearances, large-scale tours and mainstream promise, songs like House of Mirrors serve as a reminder that her success has not come as easily, or quickly, as it might appear. "I don't think it ever does," she says. "There's this whole concept of overnight success, but it doesn't really exist. Most people work at it for years before they get anywhere, and then suddenly it looks that way because no-one's heard of you until that point. But that's absolutely fine with me. People like a bit of romance."

Portrait is out now via Ark Recordings; Josephine plays Glasgow 02 Academy with Paloma Faith on January 28.