After twenty-five years, they pretty much have this routine down. But at "Riverdance," you keep dibby, dibby, dubby dubbing until you get it absolutely right. Padraic Moyles is putting the dancers through their paces ahead of a big night for the show that turned Irish dancing into a world-wide hit.

"Riverdance" associate director and brand manager Padraic Moyles leads his dancers through a rehearsal. CBS News

They're back where it all began, back for their anniversary gala on the same stage in Dublin where "Riverdance" became an unlikely, accidental show-biz phenomenon – back with a group of dancers who weren't even alive 25 years ago.

And back with a new star, a flaming-haired, 22-year-old named Amy-Mae Dolan, who looks like she was born for it.

"It's really hard to remember the first time I watched 'Riverdance,' or even heard the music, because it's literally been a part of my every day since I was born," Dolan said. "My parents love it."

"You can't remember world where there wasn't 'Riverdance'?" asked correspondent Mark Phillips.

"No, that's it. I was obsessed with it. It was just all I knew, and all I wanted to do."

It was three years before Dolan danced her way into this world, that Jean Butler and Michael Flatley stomped their way to international fame during the 1994 Eurovision Song Contest TV extravaganza, held that year in Dublin. When the last heel hit the floor, the place went crazy.

The first iteration of "Riverdance" performed at the 1994 Eurovision Song Contest in Dublin. CBS News

"And when it finished, there was this primal roar as four thousand people, as one, they jumped to their feet," said John McColgan, who with his wife Moya Doherty produced that original six-minute-and-forty-second "Riverdance" number. "And the applause I think lasted four minutes. So, we knew certainly at that time what we had suspected could happen would happen."

It was the beginning of the next quarter-century of their lives.

McColgan said, "Then the question was, almost the next day, how do we turn this into a full-blown, two-hour show and have it ready for next year?"

And how do you do that? "With a great deal of speed – quickly, and a certain amount of panic," Doherty laughed.

If there was any doubt the show would work at full-length, it didn't last long. When the run sold out in Dublin, they thought they'd try it in London. It sold out there, too, and was brought back for a second sell-out run, even though its star dancer and choreographer, Michael Flately, had stomped out of the company by then in a contract dispute.

Touring companies brought the spectacle of "Riverdance" around the world. Riverdance

"He sent us a contract with a list of 40 demands that were absolutely impossible to fulfill," said McColgan. "So, we held the line. And it was a bit like poker. He didn't think we would. But we did."

"That's a bit of a risk; he was your star," Phillips said.

"I think it was a risk," Doherty said. "But we had to have a firm belief in the strength of the work. We were tested sooner than would've liked. But we had no option."

And where better to test it than at Radio City Music Hall in New York?

"We did two weeks, which is a big gamble in Radio City," McColgan said. "But again, we did so well that we came back, and we played Radio City for six weeks."

Phillips said, "The London audience, the Radio City audience in New York, these weren't all the offspring of Irish immigrants that were coming in? Something happened."

What happened was, the show took off. At its peak, it had three separate companies touring Europe, the Americas and Asia.

Amy-Mae Dolan said, "I think it gave Irish people confidence. It was like, we have something that's very unique and special and, dare I say, sexy to present to the world. And it allowed dancers to start traveling and bring a little bit of Ireland to places like China, Australia, Japan, that maybe it hadn't been to before."

And it's borrowed traditions from places it's been. This is what happens when Irish step meets American tap:

Clog vs. tap: "Riverdance" at 25. CBS News

McClogan said, "I wanted the show to say that we support each other and we borrow from each other, giving and receiving from each other culturally."

"And we respect each other," Doherty added.

"And broaden the appeal as well," Phillips said.

"Absolutely," said Dogherty. "It is entertainment."

"Riverdance" at 25 performs in Dublin. CBS News

It's all a long way from Irish dancing's roots in pubs where the bands still play on a Saturday night, and where the floorboards still take a beating. Why this style – all flashing feet and stiff arms by your side? There's one popular theory: "The Catholic priests in Ireland just felt like that was more religious, you know, that kind of stance," said Dolan.

"And boys and girls didn't touch each other when they were dancing?" said Phillips.

"Yeah. Yeah. Nobody had an expression while they were dancing, just their feet were moving."

Boy, are their feet moving! The only way to really see what the dancers are doing is to go to the slow-motion replay, where the level of synchronized perfection is even more evident.

The synchronization of dancers. CBS News

To complete the circle, the "Riverdance" 25th anniversary show comes back to Radio City in New York this week. And apparently, it won't end there.

Phillips asked, "Do you see an end to this? Or is this gonna stomp its way into the foreseeable future?"

"Well, I have booked this venue for the 50th anniversary!" laughed McClogan.

Doherty added, "The optimist!"



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Story produced by Mikaela Bufano. Editor: Brian Robbins.