Clannad

Clannad are an Irish family band formed in 1970 in Gweedore, County Donegal. Their music has been described as folk, folk rock, traditional Irish, Celtic and new-age, often incorporating elements of smooth jazz and Gregorian chant. They are widely regarded as a band that made Irish music widely known.
Formed by siblings Ciarán, Pól, and Máire Brennan and their twin uncles Noel and Pádraig Duggan, the band were initially known as Clann as Dóbhair; in 1973 they changed their name to Clannad.

https://en.wikipedia.org/wiki/Clannad
https://web.archive.org/web/2009030105...