A flicker of recognition shoots across Alex Trimble’s face. “Hazy, very hazy memories,” he murmurs, as if lying back in a hypnotist’s chair. “I remember being sunburnt and covered in mud, but beyond that I don’t remember the show at all.”

The topic of conversation is Two Door Cinema’s career-changing Glastonbury set of 2010, which helped kick-start the Northern Irish rockers’ slow-burning rise to indie stardom.

“It was the first indicator for us that something was happening,” says bassist Kevin ...