Their glam outfits stood out among the jeans and T-shirts, and they were seen as foreign interlopers amid the wave of Aussie pub rock.

A roadie for local band Madder Lake mooned Queen, and the crowd threw beer cans and shouted "go home you Pommie wankers".

The band belted out a powerhouse set, but it ended in tears with frontman Freddie Mercury throwing a tambourine at another jeering roadie, and announcing that Queen would be the world's biggest band.

Colourful yarns abound in a new book about the four Sunbury festivals, held from 1972 to 1975.

In 1975, an irate AC/DC cancelled their set after the preceding act, British headliners Deep Purple, insisted they wait 30 minutes before taking the stage.

And a teenage Jimmy Barnes ran away from his Adelaide home to camp at the festival.

Sunbury was dubbed Australia's Woodstock, but by 1972, rock was trumping the peace and love vibes.

Up to 40,000 fans who camped on the natural amphitheatre on a farm at Diggers Rest (it wasn't actually in Sunbury), each Australia Day long weekend, enjoyed 18 hours of music a day, including Skyhooks, Sherbet, Daddy Cool, and Chain.

Hosts included comedian Paul Hogan and then-rock journalist Ian 'Molly' Meldrum.

Billy Thorpe and the Aztecs were the undisputed kings, pounding out anthems like Most People I Know (Think That I'm Crazy), and Ooh Poo Pah Doo.

The book's author, historian Peter Evans, who was lighting director at three of the festivals, and a spectator at the fourth, played a part in founding it.

In 1971 the then 21-year-old TV technician raved to his boss, Channel Nine lighting director John Fowler, about the Wallacia music festival, west of Sydney.

When Fowler asked why you'd run such an event, Evans replied "15,000 kids times five dollars."

Fowler saw the light and assembled a crack team to stage Sunbury, including soldier and solicitor Graeme Rees-Jones and film director John Dixon as site manager.

Premier Henry Bolte and the Country Fire Authority were dead against it, but farmers George and Beryl Duncan offered their land.

The 1975 festival was dubbed 'Mudbury' after it rained.

Fowler claimed radio 3XY over-stated the rain and crowd numbers slumped to 15,000, compared to up to 40,000 in 1972. The organising company, Odessa Promotions, went bust, and the dream was over.

But the book, called Sunbury: Australia's Greatest Rock Festival, is an upbeat and affectionate account of a seminal event in our history.

Evans says reports of nudity were exaggerated, and while there was marijuana and mandrax tablets, beer was more popular.

For Evans, who went on to be an audio engineer for TV programs including Hey Hey It's Saturday and The Sullivans, it was "a huge adventure".

"I was not just sitting in the audience. I had a part in it, and that made it really special".

He said people who were there often say: "It's an experience I'll never forget and it will stay with me till the day I die."