Moya Brennan’s voice was an unusual instrument to arrive in the Top 20 in November 1982, especially on a Top of the Pops episode featuring the very different delights of A Flock of Seagulls, Eddy Grant and one-hit wonders Blue Zoo. As light as a leaf in the air, it provided a sacred counterpoint to the low, looming drones of a Prophet 5 synthesiser, and, in its breathy solo lines, guided the layered harmonies of her Clannad bandmates – her brothers and uncles – to somewhere new. A week later, Theme from Harry’s Game – the closing song on a radical Yorkshire TV series about The Troubles that played out over three consecutive nights – had jumped to No 5 in the charts, the highest ever position for a song sung in Irish Gaelic.

The lyrics were about the never-ending cycle of life, and how all things must pass, plucked from a proverb from a book of her grandfather’s, by her brother and bandmate, Ciarán. Even to non-speakers, Brennan’s voice sounded like a new kind of spiritual guide, much needed in the anxious early days of Thatcherism and only a few months after the IRA London park bombings. Her impact also expanded the transportive possibilities of traditional music in film and TV. Brennan’s voice became a mainstay of soundtracks, later among them ITV’s Robin of Sherwood series, Titanic and the 2004 feature film adaptation of King Arthur starring Keira Knightley, entering public consciousness in a way similar to how the avant garde output of the BBC Radiophonic Workshop had in the 1960s.

Brennan’s singing and harp-playing initially flourished in her parents’ remote tavern in County Donegal, where they ran folk sessions and where Clann as Dobhar (Family From Dore) formed in 1970, changing their name to Clannad three years later.

Singing with her siblings and uncles, in what is known as “blood harmony”, gave her voice its capacity to blend, but also to break out – often quietly – in distinctive ways. On the band’s early albums, she is as dazzling as Pentangle’s Jacqui McShee on folk-rock stompers such as 1973’s Nil Se Ina La (Daybreak Has Not Yet Come) and 1976’s Téir Abhaile Riú (Go Home With You, Now). In 1982’s Mhórag’s Na Horo Gheallaidh, a Gaelic song collected from Canada’s Cape Breton, her visceral harmonising with her younger sister Enya hits with the same impact as the Roches or the McGarrigle sisters.

Clannad’s sound shifted after that track: the group embraced studio techniques, layering vocals in a way that evoked heavenly choirs. Brennan’s vocal leadership held this invention together, and suggested how folk’s immersion in ambient and new age music could be a commercial proposition with a woman at the helm.

She paved the way for the global success of Enya later that decade, and her influence ripples through The Ninth Wave, the suite of songs on the second side of Kate Bush’s 1985 blockbuster album, Hounds of Love, where the influence of Irish folk meets the imaginative potential of the Fairlight synthesiser. Equally, it’s hard not to think of Brennan when you hear the Beloved’s The Sun Rising from 1989 and Orbital’s Belfast of 1991 – rave tracks that sample a 1982 performance of Hildegard von Bingen’s 12th-century composition O Euchari by English ensemble Gothic Voices. In 1999, Brennan re-recorded lines from Theme from Harry’s Game for Chicane’s Euro-trance monster, Saltwater, pushing her appeal into the realm of ecstatic, hands-in-the-air rapture.

Brennan found her own rapture in Christianity, and talked often about finding her faith powerfully in nature, as well as her singing. She would continue to explore the resonances of her voice through the decades, collaborating with artists including Bono, Bruce Hornsby and the Blue Nile, and in recent years recording four albums of traditional voice and harp music with harpist Cormac de Barra. In 2020, a few months before her terminal diagnosis with pulmonary fibrosis, comedian Tommy Tiernan asked her to sing an Irish song on his RTÉ show. Her a cappella rendition of Clannad’s Gaoth Barra Na dTonn (Wind on the Waves) was remarkable. Supple, unshowy and profoundly moving, it reduced Tiernan to tears. Brennan kept touring, even throughout her illness, as recently as last year: a spirit-lifting force until the end.