NOCTU is the name of an exciting, sometimes violent and decidedly sexy new dance work by Irish choreographer and former Riverdance principal dancer Breandan de Gallai that will begin at the Irish Repertory Theatre on September 6 and run through October 2.

It’s an appropriate venue for a performance that takes an axe to the frozen sea of Irish tradition, because that’s what the Irish Rep has been doing onstage for decades itself. Without much fanfare NOCTU has arrived as a shockingly new Irish dance performance that seems calculated to divide the critics who enjoy the work’s beauty, whilst questioning its formal choices.

But director and choreographer de Gallai welcomes all that controversy. Having toured the world on the Riverdance stage, the director and chorographer had ample time to think about what does and does not work on stage in Irish dancing. He also had time to contemplate what, if anything, has been missing. NOCTU is the result of years of exploration.

Since 1994 Riverdance has launched the careers of countless Irish dancing stars who would still only have good things to say about the whole experience, but after the first few minutes of NOCTU unfold you’ll realize that Riverdance never looked this provocative or took these kinds of risks.

First of all there’s the costumes. For the men that features chest bearing black kilts or simple white slip on’s; for the women it means barely there white two pieces.

Vulnerability, passion, nudity? This is hardly the traditional get-up at your local Feis Ceoil.

The Irish Rep’s producing director Ciaran O’Reilly told the Irish Voice why the theater decided to open its fall season with the new work.

“Breandan came by to see myself and artistic director Charlotte Moore and he basically pitched it. He brought along some stunning video of the performance in Ireland, which he was about to take on a national tour, and it just blew us away,” says O’Reilly.

“How vigorous and young and vibrant and sexy it is. It really took us further than anything we had ever seen in Irish step dance. He was able to break into other forms as well as holding onto traditional ones. It’s certainly fantastic to look at.”

Irish traditional dance enthusiasts come in many forms, and the only thing that unites them is disagreement. Some argue that the traditional steps have been handed down from time immemorial and they should be preserved forever without change or alteration.

But others say that modern Irish dancing is a modern reworking of a lost art, and innovations that respect the spirit of the tradition should not have to be bound to it.

You’d be surprised how passionate these abstract debates can become in real life.  Spend five minutes trawling Irish traditional dance discussion boards and you’ll see the ease with which people insult and belittle each other’s efforts with the same fiery intensity we have come to expect on American Idol.

It’s a serious business, art, in other words. And so is the business of growing up, which gets explored in the show.

“It’s about Irish stepdancers or just young Irish people, funding their way in the world in the world. It exposes their inner turmoil. It explores the pain and joy of being an Irish stepdancer. It’s certainly an inside look at that,” O’Reilly says of NOCTU.

After his many years with Riverdance de Gallai worked as a master choreographer, and he could restage the whole of Riverdance simply from memory.

“He’s very much a part of the tradition of that, but he’s not afraid to step outside of it,” says O’Reilly.

“There’s music in the new show that’s certainly well away from stepdancing music. There are other surprises too.

“There are those who bitterly object to Breandan de Gallai taking liberties with the form in any way at all, but he’s unfazed. Many people still feel that it should all be frozen in time. So we’d be interested to see if any controversy erupts over this one. We half-suspect it’s going to.”

The Irish Repertory Theatre is located at 132 West 22nd Street. For tickets and showtimes call 212-727-2737 or visit www.irishrep.org.