In 1981, Henry Mountcharles had an idea: He wanted to transform the yard of his castle home into a music venue.
At the time, it wasn’t exactly a popular idea. Some locals called and told him he was creating “a public urinal.” Others questioned the wisdom of planning the event during such a painful moment. (This was the height of the harrowing period in Northern Ireland known as “The Troubles”—roughly 30 years of sectarian violence and bloodshed; 1981 saw the hunger strike of nearly...