Some of the most popular acts in Australia, including Wolfmother, Jet, Paul Kelly, Gabriella Cilmi, Kasey Chambers and internationals Kings of Leon and Jack Johnson will play the Sound Relief bushfire benefit at the MCG on March 14.

In a major coup for organisers, Labor MP Peter Garrett has agreed to reunite with iconic Australian rock group Midnight Oil.

Midnight Oil, Hunters & Collector and Split Enz will reform especially for the Melbourne event, while Coldplay (acoustic), Eskimo Joe, Hoodoo Gurus and Icehouse will play the Sydney version of the show held simultaneously at the SCG on the same day. Jet and the new look Wolfmother will play both cities.

Each band will play about 20 minutes of hits.

Organisers of what Premier John Brumby called "the biggest music event in Australian music history" expect more than 100,000 people attend the shows. With all involved donating their services, they hope to raise about $5 million for charity.

"Between the two cities, there's a multi-million dollar bill there, but it's costing us zero," said Sydney co-organiser Mark Pope.

With two of the most popular international bands in the country, Kings Of Leon and Coldplay, both touring here at the same time, the chosen date was a no-brainer. Both bands will play in the mid afternoon before preparing for sold out shows that night.

The Bushrangers Victorian cricket team has agreed to move its home Sheffield Shield final from the MCG to St Kilda's Junction Oval.

"Everyone in Australia wants to help in some way," said Kasey Chambers.

"I can't put out fires, I can't rebuild houses, but I can use my position as a musician to help raise some money and hopefully inspire people to help find their thing that they can do."

"It's pretty easy for us as musicians to turn up for half an hour and play music," said Wolfmother's Andrew Stockdale. "These people are going to have to do a lot of work for years. So if we can raise as much money as possible to help them rebuild their lives, then that's the least I can do."