A nationwide rendition of the national anthem and an overt display of military muscle are among new features on the January 26 line-up, unveiled aboard the HMAS Canberra on Thursday morning.

Before a performance by children from the NSW Public Schools Aboriginal Dance Ensemble, Australia Day Council of NSW chairman Angelos Frangopoulos revealed a packed schedule of Sydney Harbour races, Aboriginal ceremonies, concerts, sports events and military displays touting the biggest day of celebrations the city has seen since 1988.

But perhaps the most ambitious element of the day is the council's hope that Australians far and wide will down barbecue tools and cold stubbies at noon and stand shoulder-to-shoulder in song for a mass rendition of Advance Australia Fair.

Mr Frangopoulos said organisers had pushed hard to design a moment in the festivities that will unite all Australians and bring the diverse country together, settling upon synchronised choirs around the harbour, which will lead spectators in song before a 21-gun salute as part of the "ceremonial display of respect".

"We encourage people from all over Australia to stop what they are doing and join us in singing the national anthem at midday," said Australia Day 2015 creative director, former Australian Idol music director, John Foreman.

Taking centre stage in the salute and amid the flotilla of vessels large and small on the harbour this year will be the Royal Australian Navy's newest and largest warship, HMAS Canberra, which will be berthed between the Opera House and the Harbour Bridge.

Mr Foreman has also overseen the introduction of two free Opera House forecourt concerts - a morning session for children and a twilight show featuring Jessica Mauboy, Sheppard and Justice Crew - and a "Cruising Concert" helmed by singer Darren Percival, that will deliver music to beachgoers, park picnickers and boaties wherever the floating stage travels.

As a "counterfoil" to the pomp of the Salute to Australia, Mr Foreman said the new Tug and Yacht Ballet will tap into Australian larrikinism while in the city, a tract of astroturf will convert a section of George Street into an urban croquet lawn.

The Salute to Australia, which also involves a flyover of RAAF jets and efforts by the Army, signals heightened military involvement on the day, which commemorates the arrival of the First Fleet to Port Jackson in 1788.

HMAS Canberra was commissioned in November and is the star vessel in the Navy's relatively modest fleet. The logistical challenge of moving the 230-metre long ship into position on one of the harbour's busiest days comes at the end of a long process, said Mr Frangopoulos as he admitted it has taken years for organisers to persuade the Navy to be involved in the celebrations on such a grand scale.

"This is by far the biggest and most ambitious Australia Day we've staged," said Mr Frangopoulos.

Those of us who struggle to remember lyrics beyond the first verse of the anthem's "joyful strains" might well agree. 

Sydney's Australia Day events

WugulOra Indigenous Ceremony: 7.30am, Opera House Northern Boardwalk

Great Sydney Swim: 8.30am, Farm Cove

The Wiggles Australia Day Concert: 10am, Opera House forecourt

Ferrython: 11am, Sydney Harbour

Nickelodeon Australia Day Summer Playground: 9am-5pm, Hyde Park North

Salute to Australia: 12noon, Sydney Harbour

Tug and Yacht Ballet: 12.05pm, between the Sydney Harbour Bridge and the Opera House

Cruising Concert: 11am-4pm then 6pm-7pm, Central Harbour, Athol Bay and Darling Harbour

The Australia Day Concert at the Opera House: 7pm, Opera House forecourt

Darling Harbour Fireworks Spectacular: 8.45pm, Darling Harbour

Full information online at ww.australiaday.com.au