The most moving part of Centenary, it is generally agreed, was Colm Wilkinson's haunting performance of One by U2, during which portraits of ordinary Irish people were flashed on video screens.
The simplicity and honesty of the moment was deeply affecting. It declared that, despite our differences, we were all of us Irish and on a journey together.
But it was Wilkinson's tingling delivery that truly took the performance somewhere special. A veteran of the stage, Wilkinson (71) will already be familiar to fans of classical music and musical theatre.
However, to a younger generation this may have been the moment they were introduced to the singer, who was born in humble circumstances in Drimnagh and has graced stages across the world.
He will be forever synonymous with Les Miserables, the blockbusting 80s musical in which he played the original Jean Valjean (the role subsequently portrayed by Russell Crowe in the movie adaptation).
Wilkinson was a stunning Valjean, transmitting the same mix of reverence and emotion that he brought to his interpretation of One at the Bord Gais Theatre on Monday.
Indeed, it was arguably his rafter-raising rendition of show-piece ballad Bring Him Home that won Les Mis much of its early acclaim.
He was thus the perfect choice to sing One - bringing a lifetime of experience and an understanding of the ways Ireland has changed, for better or worse, across recent decades.
Wilkinson has lived for most of the past 27 years in Canada with wife Deirdre (they have four grown up children). Yet he remains proudly Irish and has spoken with warmth of his days as an up-and-coming local singer, where he would rub shoulders with future icons such as Luke Kelly of The Dubliners.
What made his emergence as one of the great Irish voices especially noteworthy is his ordinary upbringing. Wilkinson was born in west Dublin in 1944, in the living room of the family home. His father laid asphalt for the council but at weekends strummed a banjo in a trad band. Wilkinson's love of show business was further encouraged by his mother, an enthusiastic performer of amateur drama.
But his rise was not exactly straightforward. Wilkinson passed through local rock groups in Dublin and was cast as Judas Iscariot in an Irish production of Andrew Lloyd Webber's Jesus Christ Superstar. This opened doors in the West End and Broadway and, eventually, led to Les Miserables.
Yet the musical suffered dreadful early press - so bad, in fact, that producer Cameron Mackintosh considered pulling the show before it turned into a money pit. The reviews were heartless, too, with Les Mis dismissed as gloomy and ponderous. Yet it was its very stateliness that drew audiences and elevated Wilkinson to the highest tier of musical theatre.
"It was complicated, not exactly a bundle of laughs," he told this writer several years ago. "And the critics panned it... They called it 'the glums' because it was so dark.
"Cameron Mackintosh came into the dressing room and said to us 'I just don't understand why the critics don't like it'.
"Then one day he tried to ring the theatre and nobody answered. Eventually someone picked up. They said 'you're lucky you could get through - the phone has been hopping. There are queues around the block'".
Careers in music tend to be short. But Wilkinson has remained at the top by displaying an almost monastic discipline.
"I knew people like Luke Kelly from The Dubliners," he told the Irish Independent in 2013.
"They'd be always saying to me 'oh come out with us'. So once or twice I would go out and inevitably return home very late.
"The next day, in front of an audience, I'd feel it immediately. The energy levels weren't there. Straight away you'd say to yourself 'oh, I shouldn't have been out last night'.
"You have to be totally fixated on your voice and your energy. That is one of the things that is constantly on your mind. It takes over."
Even if Les Mis hadn't come along, he would have had an extraordinary career. At the very moment Mackintosh was lining him up as Jean Valjean, Andrew Lloyd Webber had sounded him out as potentially playing the lead in a curious new production he was testing out.
The impresario wasn't sure it would work - but felt Wilkinson was the man for the job.
"Andrew Lloyd Webber asked me to do Phantom. I was already contracted to do Les Miserables. I did the workshop of Phantom down in his home so they could put something on for potential investors - in the industry they are called 'angels'.
"I remember afterwards sharing a car home with Cameron Mackintosh. He said 'I know Andrew wants you to do Phantom - but I need you to do Les Mis. If it doesn't work out, you can do Phantom'.
"It goes to show - he didn't know whether Les Miserables was going to be successful or not. So I never got to do Phantom. The part went to Michael Crawford instead. I've never been sorry about that choice, by the way."
- Ed Power