Sydney Opera House celebrates 50 years as one of the greatest masterpieces of the 20th century

It's one of the greatest buildings of the 20th century. Fifty years after the Sydney Opera House opened its doors, we look at how this bold experiment has shaped Australia.

It's become a focal point for social, cultural and political expression.

In 2003, two men protesting against the invasion of Iraq scaled its famous sails and daubed the words "no war" in bright red paint.

It's been a canvas for art and a billboard for messages to the community.

A world heritage-listed masterpiece snapped and shared a billion times.

And a stage for countless moments in history.

Including the triumphant reception for a newly-freed Nelson Mandela, who thanked Australia for its stand against apartheid.

It's also a creation that nearly wasn't built.

This is its story.

In 1954, former railway fitter turned NSW premier, Joseph Cahill, was introduced to orchestra conductor Eugene Goossens.

Sydney had theatre houses dotted through the city, but Goossens had long been lobbying for a larger centre for arts and culture. Luckily, Cahill had similar ambitions.

The vision was to create a cultural gathering space for everyone, regardless of class or wealth, for a "better and more enlightened community".

Three years later an international competition was launched to search for the best design.

Submissions poured in from around the world, with 223 entries from 28 countries.

Recently-rendered designs provide a window into just how different the iconic landscape around Sydney Harbour could have looked, from brutalist monoliths to art deco exteriors.

One of the last entries to arrive was from an unknown Danish architect named Jørn Utzon.

However, his submission didn't make it into the group of final designs.

The story goes that Utzon's entry was picked from the reject pile.

The judging panel consisted of four men, including the Finnish-born architect Eero Saarinen.

"[Saarinen] turned up late and saw what was in the near-final pile and said 'these are all terribly boring'," Sydney Opera House CEO, Louise Herron, says.

"He fished into the discarded pile where he found Utzon's drawing and said: 'This is your Opera House'."

At that time it was only a schematic design and nobody knew how the now iconic concrete and tiled shells would be built.

Nonetheless, the judges were convinced that Utzon's sculptural design presented a concept "capable of becoming one of the greatest buildings of the world".

"Who would have thought that it would put Australia on the map?" Herron says.

"I am sure that's not something that would be replicated today."

John Bell was a young actor in the theatre when the building was taking shape and remembers a growing sense of excitement.

He says it sent a message that the city was "really serious about the arts".

"We couldn't believe we were so fortunate to have such a miracle happening, right here in Sydney," he says.

"The fact that it was in a prime spot of real estate was just magical and the design of course was staggering.

"It made a real statement that this is something absolutely essential to who we are as a nation."

However, construction took 14 years and was dogged by squabbles and cost overruns.

At times, it was feared it would never reach completion.

The original budget was $7 million but by 1973, that had blown out to $102 million. Most of that was funded by a state lottery, with $10 buying you a numbered wooden ball that was put into the draw.

Utzon famously walked out halfway through the project after falling out with the government over cost overruns.

The government halted payments to Utzon until drawings for the interiors were produced – funds Utzon argued were needed to build prototypes for his ideas.

There were protests on the streets of Sydney calling for his reinstatement but Utzon headed home to Denmark, never to return.

"One of the great myths of the Opera House is that Utzon had been ignored at the opening, that he was neither invited to come back nor even mentioned," Museums of History NSW curator, Scott Hill, says.

While recently researching the building's history, he came across a letter from Utzon to then NSW premier Robert Askin, proving this was untrue.

In the letter, Utzon politely declined an invitation to attend, saying it would be inappropriate given he was bound to criticise the architectural decisions made since his departure.

"It's a wonderful letter that he wrote. It's extremely diplomatic and it was just a great joy to come across this in the archives and to really dispel this rumour that's been so persistent for decades," Hill says.

After Utzon's resignation, the challenging task of completing the interiors fell to the Australian architect Peter Hall, who was horrified to realise he would have to start from scratch.

Louise Herron says the consequence of Utzon's departure was that "we didn't ever have the Opera House that Utzon envisaged".

The large auditorium, she says, was designed as a multi-purpose hall, with the cavernous space above the stage to be filled with machinery for rigging and moving scenery.

It instead become a dedicated concert hall. The only problem was it was the wrong shape.

Changes to his original concept meant it was plagued by acoustic problems which have taken nearly 50 years to fix. A major renovation was completed last year.

Louise Herron says it's now among "the finest halls in the world".

She quotes Sir Simon Rattle, Principal Conductor of the London Symphony Orchestra, from his visit in May.

"Standing on stage on the opening night, he said: 'You now not only have the finest outside of a building in the world, but the finest inside'."

The latest addition to one of the architectural marvels of the 20th century.

Armed with his camera, tripod and a transistor radio, third-year architecture student, Alan Croker, set off early to secure a prime place on Circular Quay to witness the opening of the Opera House.

He never dreamed that 30 years later, he would be appointed the building's Conservation Architect.

"If you had told me that in 1973, I would have said you're mad."

For almost two decades, Croker has been the person responsible for overseeing the maintenance of the building.

"Fifty years on, it's actually in remarkably good condition, thanks to the original design, the engineering, detailing and construction which were exemplary," he says.

His job involves making sure any changes adhere to Utzon's original design principles.

Everything from the finish on the paving to the colour of the outdoor furniture.

In the years before his death in 2008, Utzon wrote to the Sydney Opera House Trust requesting that the white fibreglass furniture be removed from the podium.

He compared it to an adult whose teeth had yellowed with age being given a white tooth.

"He said the shells are not perfectly white and the power of them appearing to be white and shining in the sun comes from not having anything to compare them with."

Even the concert hall signage turned out to have a story behind it.

"It has red signage on one side of the auditorium and green signage on the other side, which were to do with marine navigation for port and starboard," Croker says.

"The original tickets were sold over the counter and they had green stubs for the doors to the left and red stubs for the doors to the right.

"So if you're running to a performance and the doors were about to close, you knew it was either red side or green side and dashed to your seat."

More than one million bespoke clay tiles cover the sails and Croker says they're proving remarkably hardy, with most of the originals still in place.

About 50,000 spares have been squirrelled away at a warehouse in Sydney.

While the tiles are identical in colour, some have a translucent glaze that reflects the light.

"Utzon referred to it being as like seeing the changing lights on snow and ice," Croker says.

"One is matte, the other one's glossy. So he was looking at that same sort of approach."

Now 88, singer Kamahl has lost track of the number of times he's performed at the Opera House, but fondly remembers his first solo concert just weeks after the official opening.

"I wanted to do something people would remember," he says.

"I came up with the idea of a kaftan, a gold kaftan, with no shoes on my feet.

"And so I became the kaftan kid overnight and that continued for the next 20 or 30 years."

Over the next decade, he made regular appearances.

"There is no other place in the world that has so many memories for me," Kamahl says.

"Having done Carnegie Hall twice, this leaves the others for dead."

Indigenous dancer and choreographer, Frances Rings, says the choice of location for the Opera House was a fitting one.

Bennelong Point, or Tubowgule as it's known in the Gadigal language, has been a place for song, dance and storytelling for thousands of years.

"This site is really significant for blackfellas," she says.

"You can't be here, you can't perform here without reflecting back on the people who were here before you."

Bangarra Dance Theatre has been a resident company at the Opera House for almost two decades.

Rings says for First Nations artists, performing there brings a sense of continuity.

"We are proud to ensure that black stories are still told here on this site and that truth telling continues to happen," she says.

Louise Herron says Joseph Cahill's early vision of a cultural building for all was a bold statement about the kind of country Australia aspired to be.

There was a move away from this ethos in the ‘80s, she says, when Australia’s cultural space entered a period of "elitism and privilege”.

That’s come full circle, Herron believes, with technology and online streaming platforms helping bring the arts to all Australians, including those in remote areas.

"It's really important to us that the Opera House does belong to everybody and everyone knows they can come here," she says.

"It is a place where we want people to be empowered and uplifted and entertained.

"And to do that, we have to live up to our ambition to be everyone's house."

Reporting and writing: Ursula Malone

Editor: Nicola Gage

Photos: Keana Naughton, NSW State Archives

Digital production: Nicola Gage

Video production: Tony Park