Will

Easter service: William took time to chat to the choirboys. Photo: Getty Images

Laughter rang out and there was even the odd round of applause.

Prince William, Duke of Cambridge, and Catherine, Duchess of Cambridge, meet a Koala at Taronga Zoo in Sydney. Click for more photos

Royal Australian tour - Day 5

Prince William, Duke of Cambridge, and Catherine, Duchess of Cambridge, meet a Koala at Taronga Zoo in Sydney. Photo: Getty Images

The Duke and Duchess of Cambridge attended a thoroughly Australian Easter Sunday service at St Andrew's Cathedral on Sunday morning.

The future leader of the Church of England celebrated the day beside Australia's devout Catholic leader, Prime Minister Tony Abbott.

The Most Reverend Dr Glenn Davies, Archbishop of Sydney and The Very Reverend Phillip Jensen, Dean of Sydney, led the upbeat service, with jokes made about microphone malfunctions. A loud round of applause and laughter went up when the young Sunday School choir finished its performance then passed the baton back to the main Cathedral School choir.

Choristers, accompanied by soaring organ and brass, performed the Australian premiere of Trinity Te Deum.

''I feel pretty special,'' St Andrew's Cathedral School senior chorister Sebastian Andrews, 12, from Newtown, said after the service. ''It was a bit nerve-racking. It's not every day that you get to perform for the royals.''

He said the couple whispered to each other and appeared to enjoy the one hour and 15-minute service.

Before leaving the cathedral, the royal couple signed the First Fleet Bible, a leather-bound King James edition which was used by chaplain Richard Johnson in the first Christian ceremony held in Australia on February 3, 1788.

The bible and Johnson's Book of Common Prayer, housed at St Philip's York Street Anglican Church, are foundation documents in the formation of Australia.

The Duke and Duchess' signatures in the precious bible joined a host of other signatures from the royal family, including those of William's grandmother Queen Elizabeth, his parents Prince Charles and Princess Diana and Albert, who became King George VI.

Members of the congregation left tightly clutching orders of service.

Phyllis Lee, 58, from Maroubra, said she would keep her order as a souvenir of the day she worshipped alongside the duke and duchess.

''I'm so blessed. It was a real privilege to be in the presence of the future king,'' she said.

Sam Lau, 36, from Artarmon, said the service had been without pomp.

''It felt like a normal service. There was no special attention paid to them. It was quite laid-back,'' Mr Lau said.

Some in the 2500-strong crowd outside the cathedral were left disappointed that the royal couple did not stop to meet the public after the service, but for two people, a fleeting glimpse was more than enough.

Wendy Pearson, 48, and her daughter, Georgia, 13, had travelled from Melbourne, paying $1000 for what amounted to two seconds' of viewing time of the royals.

''It was definitely worth it,'' said Wendy. ''I loved what she was wearing.'' The duchess paired a dove grey coat by Alexander McQueen with a Jane Taylor hat.

As the motorcade swept the royal visitors away - and towards a small group of indigenous rights protesters with a ''Give back what you stole'' banner - three loud cheers went up.

On Sunday afternoon the duke and duchess visited Taronga Zoo, where the bilby enclosure was renamed the Prince George Bilby Exhibit.

When the prince came face to face with Bilby George it was a moment that gave Sydney a final look at the nine-month-old boy who is third in line to the throne.

Correction: Due to an error introduced in the production process, an earlier version of this article attributed a quote from Phyllis Lee to Sam Lau.