RóisFlourish with District Music, Saturday★★★⯪Róis arrives onstage dressed like a Victorian widow: a long black dress, black lace veil obscuring her face. Behind her, the guitarist and drummer are similarly elegant but anonymous, their features concealed beneath full black masks. The visual language perfectly complements the music’s neo-Celticism, drawing on traditional Irish forms but filtering them through something creepier and a touch futuristic: ancient folk ritual that’s survived into a post-apocalyptic world.Much of the All Together Now set draws from her latest release, Mo Léan. The opening stretch unfolds through textured, dreamlike arrangements, traditional keening refracted through electronic production, drones and spacious percussion. Róis has an extraordinary voice, both intimate and ritualistic, and she inhabits the ethereal energy of the songs. Like the costumes, they’re acts of channelling, reaching back into an imagined past, but you also can’t help but wonder if it’s a tactic, a way of withholding anything personal or risky.The whole neo-Celtic vibe is a compelling, if not very novel, visual and musical vocabulary, but it begins to feel limiting when every song occupies the same haunted register.Róis performing on the Flourish Stage at All Together Now. Photograph: Dara Mac Dónaill