When the rumours started that Baz Luhrmann was snooping around Nashville for someone to play Sister Rosetta Tharpe in his Elvis biopic, Yolanda Quartey knew she had to step up. The country-soul singer, known as Yola, is British but is based in the heartland of US roots music. She’d grown up listening to Tharpe back in Bristol and strongly related to her story.

Until recently, Tharpe’s contribution to laying the foundations for rock’n’roll in the 1930s and 40s – with her gutsy gospel singing and claw-hammer-plucked electric guitar, a huge influence on the Memphis Flash himself – had gone largely unsung in popular culture. Quartey has experienced that erasure first hand, too. Back when the 38-year-old was trying to make it in the UK, she says: “I was told by a record company exec that nobody wanted to hear a Black woman sing rock’n’roll.” She says the film is “for all the kids that have been told, because they’re of colour, that they can’t touch a guitar”, another insult that’s been levelled personally at her.

“Even though I knew that wasn’t the case,” she says, “I had to undo the mental programming.”

At first, Quartey questioned whether she should play the part of Tharpe. But she was used to being an English transplant in a very American setting. And then she thought: “Who’s gonna do it if I’m not? I don’t know if people get to see a plus-size, dark-skinned woman on screen at all at this level. I don’t see me up there enough.”

We’re about to see Yola up there, in the big time, a lot more. Not only is she starring in one of the biggest films of 2022 but she will close Glastonbury’s Left Field stage on Sunday. It’s a crucial milestone for the singer, who has risen rapidly in the US, where she now performs with the likes of Dolly Parton and Mavis Staples. Her debut album, 2019’s Walk Through Fire and its 2021 follow-up Stand for Myself – both produced by Dan Auerbach of The Black Keyswere praised for their genre fluidity, uniting the worlds of country and soul. That high regard is reflected in her six Grammy nominations. The Brit awards have yet to catch up: she’s never been nominated. “They say: go where you’re celebrated, right?” she quips.

In Nashville, Quartey is among what’s been called a “vanguard” of Black women – including Rhiannon Giddens and Allison Russell – who all used to live together and are redefining US roots music. It’s a sphere that has traditionally overlooked people of colour and change was long overdue. “We were pissed about it,” Quartey says, “and I’m like, well: ‘Let’s all do sick shit at the same time.’” They were tired of “tokenism” and the idea that there’s only room for one Black woman at the top. “It was about supporting each other,” she says, “not subscribing to the one in, one out situation that happens all the time. We can have 50,000 white guys with a guitar but we can only have one Black lady that does, frankly, anything.”

The Grammys have started to take note – this year the best American roots song category included Quartey, Russell, Giddens and Valerie June, and was won by Jon Batiste. Progress is “far from complete” but “definitely noticeable,” says Quartey. And yet the UK falls way behind. “​​I go to a jazz and blues festival in the US, I see lots of artists of colour performing. Not here. It’s embarrassing. We’re still under the illusion that this stuff doesn’t belong in the pantheon of Black music.”

Quartey was well prepped for Tharpe, having worked at a “sample replay company” in London for 15 years. There she would create soundalikes of famous music by intimately studying the vocalists, no matter the era. “It’s like singing-acting,” she says. “I have to get into the headspace of where that person was.” Additionally, she worked as a songwriter and session vocalist, appearing on a number of UK dance singles, including Blind Faith by Chase & Status. She breaks into its vocal hook: “‘Swee-eet sens-a-ti-on’. That’s little old muggins here.”

But rather than this work being yet another example of a Black woman not receiving her fair dues by white record producers, Yola says she had a gameplan. She even turned down joining Massive Attack’s band. “I hustled for years in dance music behind the scenes, and I’m one of the only people who did that purposefully. I didn’t want to put my name on tracks because otherwise that would become my brand. I get to decide what my brand is.” Around the same time, she was also fronting the Bristol country-soul band Phantom Limb, which was more in line with the Yola you hear today. Rather than gain name association, she wanted to be able to fund her own projects. “I wanted mon-ney,” she enunciates. “MONEY!”

Quartey is witty, self-assured and has a powerhouse voice that is river-deep, mountain-high, its gorgeous texture crackling like a dusty record. In conversation, she races through topics such as art versus autocracy and the time she taught “vocal biomechanics” at Bath Spa University. But she says that, despite having all the makings of a chart-topper, it’s little wonder she made a music career in the UK first. “The psychological programming that we all receive in this country tells you a narrative about Black femininity that blasts over to music.” There is a “will” to “erase dark-skinned Black women in this country from any visual or literary narrative” where “nice things happen to us”.

She says you only need to turn on the TV to see how. “Tell me the number of times you see someone that looks just like me: slightly plus, dark, in a balanced, happy family dynamic.” Or, she adds, “just a positive image of a Black woman.”

Quartey made most of Stand for Myself around the same time as working on Elvis, and they share key themes, such as the whitewashing of rock music and taking control of your own destiny. In one of the film’s most memorable sections, we see Colonel Tom Parker insisting Presley wears a twee festive jumper for a televised special. Presley retaliates by later giving the encore performance of a lifetime in head-to-toe black leather. Perhaps it’s no coincidence that Quartey is dressed today in head-to-toe black latex. She’s had people try to put her in a metaphorical Christmas jumper before, too. “I’ve had managers like that … I’ve tolerated a lot,” she says. And then she deadpans: “The Christmas jumper is white supremacy.”

Yola is only in Elvis long enough to sing Tharpe’s Strange Things Happening Every Day, resplendent in gold satin, guitar strapped on, in a club on Memphis’s fabled Beale Street. And enough for us to hear that Tharpe discovered Little Richard (her queerness or direct influence on Elvis isn’t mentioned). But collectively, along with Richard, BB King, Big Mama Thornton and Big Boy Crudup, these artists’ presence in the film underlines that hip-swivelling music in no way started with the “king of rock’n’roll”. But also that he wasn’t as guilty of nicking Black music as some might think.

“We’ve made Elvis a bit of a whipping child of appropriation,” says Quartey, “but we haven’t had the full story. Without being a, like, appropriation apologist, he’s growing up as the token white guy in Blacksville – how are you not going to be exposed to that [music]?” The film at least faces up to the implications of these things. In one scene, Elvis tells BB King that he’d love to cover Little Richard’s Tutti Frutti and King responds that Elvis would make more money with it than Richard could ever dream of. “This movie doesn’t dance around the uncomfortableness,” nods Quartey.

Nor does she: Yola is taking over screens, muddy festival scenes and, later this summer, two shows in London, without ever shying away from saying what she thinks about subjects that are too often avoided. It’s going to be a huge homecoming. “I have a mission,” she says, “and I’m extremely bloody-minded about it.”

Yola plays Koko, London, on 20 and 21 July and headline Glastonbury’s Left Field stage on 26 June. Elvis is in cinemas from 24 June.