‘Run and tell everybody that Laetitia is a small fish … and you’re a shark that eats every fish,” sings Laetitia Tamko, aka Vagabon, on The Embers, the punky shebang that resonates more strongly than any other song of this short show. It’s certainly the one that has the audience most vigorously indie-dancing – swaying from the waist upward – and singing along. Of the eight tracks on Vagabon’s debut album, Infinite Worlds, The Embers is the strongest (and catchiest) expression of feeling small and overwhelmed; the fans’ response feels like a gesture of solidarity.

Tamko is a Cameroon-born 24-year-old who moved to New York at 14 and gravitated to Brooklyn’s DIY rock scene, where she wondered why there weren’t more “weird black girls” involved. Vagabon offers encouragement to anyone else who feels institutionally marginalised and might be minded to make inroads into a traditionally white genre, but it’s also Tamko’s own story. Backed here by a drummer and a bassist, who heighten the raw sound she produces with voice and guitar, Tamko faces her songs head-on.

One of her themes is the shifting-sands sensation of being buffeted between cultures. On Minneapolis she sings: “I can’t go back to the place where I once was … where I was born.” Its recorded version makes her sound lost; on stage, she confronts her confusion and owns it. Warning the audience “it’s gonna go really loud and my ears are gonna bleed”, she shreds and the drummer piles in; ears probably do bleed. Her vocal halfway between a sob and a Patti Smith-esque atonal shout, Tamko pulls off a ragged triumph. Cold Apartment, which bitterly regrets a breakup, is switched up from its folky recorded version into mad ululations, as if the split has only just happened.

Despite the heartbreak she’s soldiering on, inviting us to the merch table after the show, where she’ll “be giving out free love advice” (although an attempt to sample her advice is thwarted by the length of the queue). But the most arresting song of the eight played tonight is the new one that closes the set. The words are impossible to make out thanks to a monstrous synth drone, but she sings it solo, holding the mic a foot from her mouth – her voice is that powerful – and it sounds like a clarion call to others who want to join her as one of indie’s new brooms.

• At Night & Day Cafe, Manchester, 18 October. Box office: 0161-236 1822). At Thekla, Bristol, 19 October. Box office: 0117-929 3301. At Green Door Store, Brighton, 20 October. Box office: 07944 693 214.