Produced by international advocacy body Global Citizen, Sunday's event has been created for broadcast viewing on myriad networks and platforms to call for coordinated action on vaccine equity, extreme poverty and climate change.
The organisation's global board members include senior executives from Cisco, Live Nation Entertainment, TED and the Bill and Melinda Gates Foundation.
The seven-strong Australian board includes former Democrats senator Natasha Stott Despoja.
Timed to coincide with the UN General Assembly, next month's G20 and the COP 26 UN Climate Change Conference in November, the organisation is calling on Australia to commit to reducing domestic emissions by 74 per cent by 2030 and achieve net zero by 2050.
Global Citizen is also urging the government to set new science-based targets in line with the Paris Agreement to avoid a greater than 1.5C rise in temperatures.
Finally, the organisation wants Australia to donate further COVID-19 vaccines and funding to its regional neighbours to ensure equitable access.
Co-hosted by Hugh Jackman in London and his wife Deborra-Lee Furness, in New York, Global Citizen Live will include performances by Kylie Minogue in London and Keith Urban in Las Vegas. Cathy Freeman and Celeste Barber will also make appearances.
Goodrem will be the only artist performing from Australia.
Not only that, but given the strict, COVID-safe protocols in her hometown of Sydney, she'll be pretty much on her own, at the piano, outside the eastern sails of a certain well-known building.
"We're in lockdown and there are so many restrictions, but I am going to give it my absolute heart and soul, and fly the Australian flag from the iconic Sydney Opera House," she says.
"Every country has had their path out of this, and this is where we are, and I accept that as a performer," she says.
"I would love to be with a live crowd, but you can see crowds if you watch the concert in some of the other cities."
Although she'd prefer to keep the set list a surprise, Goodrem will perform The Power from her recent sixth studio album, Bridge Over Troubled Dreams, along with three other tracks on Sunday at 9pm.
"This has been all about going back to where it started for me creatively, which is the piano," she says.
Goodrem, 36, successfully fought Hodgkin's lymphoma early in her career, and is a long-time advocate for a range of cancer-related and other charities, including the Kinghorn Cancer Centre, of which she has been patron since 2009.
She is similarly inspired by how easy Global Citizen makes it for people to get involved in a cause that is meaningful to them.
"You can go on their website and see all the different ways you might find your passion, whether it's saving the planet, defeating poverty, or vaccine equity," she says. "It's about finding what hits your heart."
Goodrem has been hitting listeners right in the heart ever since her breakout debut album, Innocent Eyes, in 2003, which has sold 4.5 million copies around the world.
She has since released a further five studio albums, four of which have gone to No.1, and bagged 12 ARIAs in the process.
"Music has always been about healing, for me, and I know how it can change the energy in any room," she says. "It is an equaliser."
Although she's performing, Goodrem is as enthusiastic as any fan girl when it comes to who else is on the bill, not least because she's worked with a few of them.
"I was fortunate to tour and sing with Andrea Bocelli, who will be appearing from Tuscany," she says.
"The incredible Ricky Martin, who's in Las Vegas, is a dear friend and I've also duetted with him. And of course I've worked with Keith Urban on The Voice."
Given one of the tracks on her new album is titled Dear Elton, she's not about to miss seeing her idol perform in Paris, either, alongside the likes of Ed Sheeran and the Black Eyed Peas.
"I have so much love and admiration for Sir Elton, the master of the piano," she exclaims.
"So there really is an amazing community of artists involved, and I am so grateful to be part of such an incredible moment."
Global Citizen Live is live-streamed from 3am Sunday on 9Now.