There are few artists more beloved to Australians than our Farnsy.

You don't have to follow music at all to know just about every word to You're the Voice. Some would argue it's Australia's true national anthem (though it may have competition from Flame Trees and The Horses).

But John Farnham's soaring 1986 roof-raiser didn't just arrive into being fully formed, ready to capture the hearts and minds of the Australian public. A whole lot happened behind - and in front of - the scenes before that classic song ever got to that stage.

And that's all explored in the exceptional music documentary John Farnham: Finding the Voice.

If you're a Johnny Farnham fan, it's a must-watch. If you follow the Australian music scene, it's a must-watch. If you enjoy stories of Steven Bradbury-esque comebacks, it's a must-watch.

The doco, directed by Poppy Stockwell (who has just a few previous films to her name), introduces us to a very young John Farnham, arrived fresh in Australia from the United Kingdom.

There's some home video footage of the smiling blond kid, images few have probably seen outside the Farnham family.

Starting with a local band in the 1960s, Farnham's voice is eventually picked out by the man who will become his first manager, Darryl Sambell. Looking like a villain from a 1970s crime drama, Sambell is not remembered particularly fondly by any of the talking heads in the film.

Sambell sets the teen Farnsy up with a gig singing a jingle for Ansett airlines, then comes his enormously huge break - Sadie the Cleaning Lady. Never mind that Farnham was more interested in rock and roll than happy ditties at the time, his manager decided this was the direction they'd be taking, and decided to dress him like the Johnny Walker label (minus the top hat).

It's in this period that we start to see the first cracks forming. Despite his national, chart-topping success, Farnham feels the beginnings of depression. There's a vulnerability to the singer that will follow him his whole life, and is taken advantage of in the wrong hands.

Farnham's journey from overnight juggernaut to cringey forgotten pop star is sad, and if you've only grown up knowing about Farnham the legend, then this portion of his history may come as a surprise.

While the man himself doesn't appear on camera for interviews, and is seen only through archival footage - of which there is, gloriously, plenty - there are a host of important figures from Farnham's life who help flesh out the story of how he became one of the biggest and most revered names in Australia pop culture.

We hear, through voice only, from his great pal, the late Olivia Newton-John, and from wife Jill Farnham.

Speaking to camera are the likes of Farnham's two sons, friends Jimmy Barnes and Daryl Braithwaite, band members David Hirschfelder, Tommy Emmanuel, Brett Garsed, Angus Burchall, Venetta Fields, and even international fans like Celine Dion and Robbie Williams.

Providing probably the greatest insight are Farnham's late manager Glenn Wheatley, whose death affected him greatly, and his wife Gaynor Wheatley. The Farnham-Wheatley connection is the heart and soul of the doco, and, it seems, both men's lives. It's beautiful to watch.

Prepare to sing along, tear up, and sing along again. Even after all these years, You're the Voice can still cause goosebumps.