One to watch: Bipolar Sunshine

"Spellbinding," says Adio Marchant, the 29-year-old musician who performs as Bipolar Sunshine. We're in the enormous hull of London's Brixton Academy, the only people in here bar a sound guy – and Phoenix, rehearsing energetically on stage. The French superstars will headline Brixton tonight, with Marchant in support. "There's a reason why certain people get to a certain level," he says. "I can only learn from these guys; they've done such great things."

He's done one or two great things himself. Like many, I first caught on to the quality of Marchant's Bipolar Sunshine act after hearing his 2013 track Fire. Part soul, part electronica, with hints of gospel and a generous scattering of cheese, it was a five-minute stunner. Bruised vocal first; then mellow, Manchester-accented spoken word; and after that (absurdly) a sampled chunk from Hollywood weepy The Notebook. This shouldn't have worked at all; "Even I wasn't sure at first," says Marchant. "That film has connotations, people think it's cheesy. But when we put it in… it felt right."

With a new single out, a debut album coming, Marchant's on a good run, tonight's support slot at the Brixton Academy one of five gigs at the venue in the space of a fortnight. (As well as the Phoenix dates he's a guest vocalist for the drum'n'bass act Rudimental.) Not so many years ago he was working in a failing furniture store, "the shop floor as big as the Brixton Academy, and about six customers a day".

Marchant grew up in Parrs Wood in Didsbury, eldest son of Jamaican Mancunians. He describes himself as a rare thing at school: a black Oasis fan. "I cared about Oasis and about hip-hop. I knew both. I've always been that guy who can hear good from left and right."

His parents separated when he was young; Marchant grew up very close to his maternal grandfather, "a massive influence on me, basically a dad". He'd hoped for a football career, but after trials he failed to get a contract. "I was lost." He spent two years at the furniture shop, then did a stint at music college before forming a ska band, Kid British. They had a good few months, releasing singles, being interviewed. "Then everyone stopped listening."

These days, at gigs, Marchant performs in front of a projection of his grandfather's favourite film, Gone With the Wind: a tribute. He died shortly before Marchant disbanded Kid British. "There were so many things going off in the band. And when my grandad passed I thought, 'You know what? I'm gonna give music another try. But I'm gonna do it how I want to do it.'" He started working with a producer called Jazz Purple, billing himself as Bipolar Sunshine.

That name… I tell him: people might find it disrespectful, even offensive. He says that wasn't the intention. "I like the juxtaposition. And it fits the music I write. Never one particular style. Some days are joyous, some days low."

Labels must have protested. "I've had those discussions. But if they weren't gonna allow me to go with my creative vision then I ended it." (Marchant is currently with Polydor.)

Well, sneaking The Notebook on to a serious piece of music shouldn't have worked, yet did. No doubt he can pull off a tricky dodge and overcome objections to the name. "Sooner or later I want the songs to take over. When you first heard of Coldplay, you didn't get the [combination of] words, right? Then you hear the music and you're set with what Coldplay is. You understand."

Bipolar Sunshine's Where Did the Love Go is out now; he tours from 27 March