Padraig Duggan, who played guitar and mandolin with the Grammy award-winning Celtic fusion pioneers, died in a Dublin hospital after a recurring illness.
The band – siblings Ciaran, Pol and Moya Brennan and their twin uncles Noel and Padraig Duggan – achieved huge international success over their 40-year career.
Their distinctive and haunting sound sold more than ten million albums worldwide.
“My dear uncle and Clannad member Padraig Duggan passed away peacefully this morning,” Moya Brennan wrote on Twitter.
“Rest in Peace Padraig.”
Clannad formed in the early 1970s with regular performances at the family’s music pub, Leo’s Tavern, in Gweedore, Co Donegal.
Another of the Brennan siblings, Enya, left the group in 1981 to embark on a hugely successful solo career.
Their unique take on traditional Irish songs, coupled with contemporary influences, won them a folk festival competition and a record deal.
Their breakthrough hit Harry’s Game, theme track to the TV series of the same name, came in 1982.
Worldwide acclaim and a global touring schedule followed, with a string of albums and well-known hits including In A Lifetime, with Bono.