After being 'discovered' on YouTube, a regional Australian high school choir has impressed a crowd at one of the world's most prestigious performance spaces.

After posting a video of their chamber choir singing on YouTube, students from the St Columba Anglican School in Port Macquarie, on the New South Wales mid-north coast, were invited to perform at New York's Carnegie Hall under renowned composer, Paul Mealor.

At first it seemed too good to be true and was dismissed as a joke.

It turned out to be the real deal and the students have just returned home from their fairytale experience, after delivering an amazing choral show in New York.

Chorister Harley Coleman said at times it was hard to believe.

"It was surreal, I think when we walked on the Carnegie Hall stage for the first time, that was the moment we went, 'Oh here we are, this is really all happening'," he said.

The students have described their experience in a large international choir in Carnegie Hall as 'surreal'. ( Supplied: Dan Wright Photography/DCINY Production )

Milana Cooper agreed.

"The whole entire experience felt like a dream," she said.

"When I came back I just thought, wow, that was such a big deal, we are all so young, and to have this opportunity was a great experience."

Fellow chorister, Kate Foy, said it had opened their eyes to a whole new world.

"I had a lady sitting behind me with a thick French accent and there was a person next to me from Hong Kong and it was great to exchange stories of how we got there," she said.

"They were like, 'What? You came from a tiny town in Australia?'

"So it was really good."

The students said they were more excited than nervous.

"Everyone was very happy and a lot of work and effort paid off in one performance," student Laura Stewart said.

Remembrance Day performance

Port Macquarie's St Columba Anglican School Choir spent many hours rehearsing in their home-town of Port Macquarie in the lead up to their trip to New York. ( Supplied: St Columba Anglican School )

The performance was held in Carnegie Hall on Remembrance Day, where the students performed Paul Mealor's, 'Requiem: The Souls of the Righteous' as part of the mass Distinguished Concerts Singers International Choir.

Student Nicola Awad said they had all gained a lot through their performance with Mr Mealor, whose work was performed at the royal wedding ceremony of Prince William and Kate Middleton in 2011.

"We learnt that there's definitely a bigger world outside our little country town," she said.

"To have been able to sing in possibly the world's greatest performance space with Paul Mealor, who we've looked up to and has inspired us, it's just such an honour."

Student Greg Mitchell said the experience had been invaluable.

"I definitely gained a greater sense of musicianship from Paul Mealor because he had such a great way of composing the music that really brought out the emotion in the music as well," he said.

Times Square, metro trains and an HSC exam

The St Columba Anglican School students took time to explore some of the sights in New York during their trip and said it broadened their horizons. ( Supplied: Dan Wright Photography/DCINY Production )

Choir Director Marie Van Gend, who sang with the choir in New York and worked hard during the year to help prepare them for the performance, said it has been a life changing experience for a group of country kids.

"The highlight for me has been seeing the growth in the students both musically and personally," she said.

"We have tackled the hardest thing we've ever had to try and do, and they achieved it well.

"It was terribly emotional, I had to spend my whole time not bursting into tears, it was just so extraordinary."

Ms Van Gend said the students had flourished through their travel experiences — three of them also had the added pressure of overcoming jet lag to sit their final HSC Drama exam while in New York.

They sat the exam at the Nassau Community College, which counts Eddie Murphy and Billy Crystal among its famous alumni.

These three choristers, Harley Coleman, James Sutherland and Jordan Magnus-McCarthy, were all smiles after successfully sitting one of their HSC exams while in New York. ( Supplied: St Columba Anglican School )

"They have grown as people, their confidence during the eight days in New York, it was just fascinating to see it grow," Ms Van Gend said.

"We had to tackle metro trains, fight our way through thousands of people in Times Square, we did pop-up choirs throughout the city, and they just thrived, they were positive and confident, and they have carried that through their return.

"In their first rehearsal since our return there was a vibrancy and energy that will be the legacy of New York I think."

Trip initially dismissed as a joke

The school students are still on a high after their performance in New York. ( Supplied: Dan Wright Photography/DCINY Production )

Ms Van Gend said it was lucky the trip happened at all, as when she first received the invitation to perform at Carnegie Hall she thought it was a joke or scam.

"I was at home and I got an email from a person called Maggie saying, 'Hello Marie I hope this finds you well, I've just watched a video of your choir on You tube singing Paul Mealor's music, would you like to come and sing in Carnegie Hall'," she said.

"I didn't believe her and deleted it.

"Luckily she chased me up and we found out it wasn't just some shonky deal, it was the real thing."

New doors have already opened

The students were thrilled to sing under famous composer/conductor Paul Mealor and even had the opportunity to interview him while in New York. ( Supplied: St Columba Anglican School )

The experience has already opened doors for the regional school choir, with details to be revealed of another international performance.

"Mr [Paul] Mealor has been commissioned to write a big work and he came up and asked us if we would please be part of it, so that's very exciting," Ms Van Gend said.

Chorister, Jordan Magnus-McCarthy, said it was an experience they would not forget.

"It was a premiere not just for the music but for us as well, almost like our first hurdle into a big industry," he said.