Later, I found that angel was Maire Brennan (later to be re-Anglicized Moya Brennan), lead singer of Clannad and cousin to the rest of the band. I started picking up their music, Moya's music, and then her sister Enya's. That has been quite a rabbit hole.
One of the Clannad members has passed, and the rest are above 70 and tired of touring, so they've declared the 2021 tour their last. I bought tickets to a show in Minneapolis that they just cancelled, so the Scotland trip is getting detoured to a trip to NYC for that concert. If I can score a Dead Man Fall show while I'm in Glasgow, I'll have at least 3 concerts in 2 weeks.
Hearing Ms. Brennan in person will be worth it.