Members of the ACO perform in the shearing shed at Gnaraloo Station. Credit:Ed Sloane It was bold. It was brave. It was expensive - $250,000-plus, according to the ACO. It was also fun. ''Look at that, eh?'' Tognetti said, sitting in his tent overlooking the Indian Ocean. The heat was like a hammer; the wind incessant. We were both feeling salty and pleasantly sore, having been surfing all morning. ''I don't know how we ever convinced the ACO board to have us here.'' To chamber music traditionalists - to anyone - The Reef must seem a strange idea. In one sense the project is a marriage of Tognetti's two great passions, music and surfing. For Tognetti, who grew up in Wollongong and rides a highly experimental - and fiendishly difficult - finless surfboard, surfing is ''the perfect intersection of mind, physical culture and art''. Exploring what he sees as the natural dialogue between these two pursuits has allowed him to take the ACO into uncharted territory, not only in terms of the music itself, but its audience. Traditional classical-music audiences, the kind who fill recital halls and opera houses, are not being replenished: The Reef, then, is one way of tapping into a whole new market - one comprised not only of surfers, but of anyone who has a relationship with the ocean.

A quick surf check. Credit:Ed Sloane In structure at least, The Reef follows on from the ACO's Musica Surfica (2008) project and The Glide (2009), a genre-busting multimedia performance that combined live music by the ACO with footage of the ocean and surfers, most of it shot by Victorian cinematographer Jon Frank. As with The Glide, The Reef will use pre-existing music from the ACO repertoire and new material, written at Gnaraloo. Accompanying the music will be a 100-minute film shot by Frank and directed by Mick Sowry, a Torquay-based filmmaker who also directed Musica Surfica and The Glide. (Interestingly, Sowry was never actually asked to direct the film. ''I just happened to look at the Opera House's website one day and came across an ad for something called The Reef, which said, 'Directed by Mick Sowry'. That was the first I knew about it,'' he says.) Cellist Julian Thompson hits a bum note. Credit:Ed Sloane Sowry's film will involve lots of surfing, particularly of the finless variety, courtesy of Derek Hynd, an idiosyncratic former Australian pro surfer-cum-guru of ''friction-free'' (finless) wave riding, and young Californian surfing savant Ryan Burch. But Sowry's film will also be conceptual, an impressionistic rendering of a day in the life of Ningaloo Reef, a timeless place across which humans float like motes, tiny sparks that appear and disappear into eternity.

Gnaraloo itself is ancient, raw and forbiddingly remote, a moon-like swathe of saltbush and sand two hours' drive north of Carnarvon. It is accessible only by four-wheel-drive. There is no fresh water and no power. There is, on the other hand, mobile phone reception, but only if you are very tall and the wind is blowing in the right direction. Richard Tognetti rehearses. Credit:Tim Elliott There's a knowingness you get from the dust, the surf, which becomes subtext for the music. Planning the adventure began in 2009, but just months before kick-off, Mark Atkins, one of the two indigenous musicians slated to take part [see box, overleaf], was diagnosed with bowel cancer and underwent surgery. (He still attended.) Then, a month before he was due to arrive at Gnaraloo, composer Iain Grandage's wife had a baby, making his participation sensitive, to say the least. To top it off, Hynd and girlfriend Taylor Miller, whose car journey from Byron Bay to WA was to be part of Sowry's film, rolled their vehicle on the Buntine Highway, 1000 kilometres from Broome.

Indigenous musician Mark Atkins. Credit:Edward Sloane Miller had to be flown to Darwin for treatment, while Hynd set out to procure a new windscreen and tyre. He failed to find a windscreen (they drove to Broome wearing goggles) but the mechanic who sold them the tyre threw in a half-dingo puppy, free. Hynd christened it Buntine. When I arrive, a day-and-a-half after leaving Sydney, Gnaraloo has the appearance of a Bedouin camp - if Bedouins had somehow discovered surfing. There are boards and wetsuits everywhere, lots of dust, half-drunk bottles of wine, a fire pit; snatches of violin in distant caravans. One night, in a crowded, dimly lit tent, Tognetti and violinist Satu Vanska rehearse one of The Reef's more contemporary pieces, a reworking of the Alice in Chains song Them Bones, with cellist Julian Thompson. For the vocals, Tognetti recruits two surfers, Craig, a tall guy with an extravagant handlebar moustache, and a long-haired bloke named Clay, who stand side by side, beers in hand, bashing it out like Vikings at a wake. I want to ask how such a song will fit into the final show, but pinning Tognetti down isn't easy: he is either in his tent or arranging music or sleeping or eating. And when he isn't doing any of these, he is surfing.

Indeed, surfing seems to be the first priority of the residency: the state of the waves, tides and wind dictate the shape of the day. (As well as two surfboards, Tognetti brought along a professional surf forecaster, Steve Shearer, a man whose command of a synoptic chart is nothing short of forensic.) As a surfer myself, Tognetti's approach seems eminently sensible. Here, after all, are some of the best waves in Australia: long, heaving walls of water, jade-green and sun-flared, pulsing out of the ocean like a drumbeat, with their smoking crests and wind-whipped peaks. The ocean here is deep and clear and alarmingly alive: one day while out surfing, a giant manta ray sails underneath my board; on another occasion, Frank is in the water filming Miller when they are surrounded by a posse of curious reef sharks. The sun, the sand, the wind, the water; to stand on the beach here after a long surf is to feel yourself, as Albert Camus wrote in The Sea Close By, ''at the heart of a royal happiness''. But how does this feed back into the music? On this, Tognetti is a little vague. Certainly he believes that finless surfing represents ''an adventure in going beyond your limits'', an ethos he is keen to instil in his orchestra. Grandage, the composer, is more succinct. ''The most obvious point of contact will be in the euphoric, virtuosic free-form music,'' he tells me. ''But there is also a knowingness you get from just being here, from the dust, the sound of the blowholes and the surf, all of which becomes subtext for the music.''

Grandage was also inspired by local references - the landing of Dutch navigator Dirk Hartog, in 1616, at Cape Inscription, 150 kilometres away, and the wreck of the Batavia, off Geraldton, further south, in 1629. ''There's a piece I've written, called Underneath,'' Grandage says, ''based on the idea that a shipwreck through nature's course becomes part of nature itself; that even the skeletons of the dead become part of the reef.'' Because he has worked extensively in theatre, which is collaborative, Grandage feels comfortable with the nature of the residency, which can be described, at best, as ''organic'' and, at worst, ''total chaos'', with what ends up being 50 people - musicians, surfers, film and sound guys, personal assistants and PR people, caterers, photographers, journalists, even a former SAS safety consultant - all pulling in different directions. When I first arrive, I find it hard to believe that anything coherent can come of this, but am told ''don't worry'', that things will ''come together''. Just go with it. This seems like baloney to me. But then one morning a PR woman named Chryss and I get lost while driving to meet Tognetti and the others at a secret surf spot. Getting lost in Gnaraloo is incredibly easy: there are a million sand tracks out here and they all look the same. When it is clear that we have no idea where we are, we stop and make jokes about ''how Wolf Creek this is''. Maybe we will have to eat one another. As it turns out, Chryss is a vegetarian, which is the best news I've heard all week. Eventually a Land Rover comes up behind us: the driver is going to the same spot as us; he will show us the way. ''See,'' Chryss says, ''just go with it.''

On the way back from the surf I get a lift with Tognetti, who - having been here for two weeks - knows his way around. At last, I think, my chance has come to grill him about the music, his vision, about where all this is headed. The car crests a slight rise in the track, one that affords a panoramic view of the reef and the ocean. He stops, and we sit in silence. He points to a bombora, far out to sea, where a wave is breaking. ''We surfed that the other day,'' he says. ''So amazing. Don't think I've ever gone so fast.'' Then he starts up the car again, and we drive back to camp for lunch. On the final night of the residency, there's a concert in the shearing shed of nearby Gnaraloo Station. Miraculously, the ACO has sold 190 tickets. Right on sunset, the crowd starts arriving: farmhands, fishermen and surfers, owners of adjacent stations, locals from Carnarvon, everyone ambling in with their wines and beers to sit on plastic chairs under a hot tin roof, a tornado of giant moths whirring about their heads. ''It's a once-in-a-lifetime experience,'' one woman tells me, looking as if she is about to cry. The program is typically Tognetti: an improbable mix of classics - Beethoven, Pachelbel's Canon - with pieces that should eventually make their way into The Reef, such as the Viking-like Them Bones, and a nostalgic acoustic piece by Steve Pigram. There is also Atkins on guitar and didgeridoo, and a version of Pete Seeger's anti-war anthem Where Have All the Flowers Gone?, sung by Vanska with a poise and clarity that appears to stop time. But the music of the moment goes beyond the instruments; it's in the clinking of the beer bottles, the young kids yelling, ''Look, daddy, look!'', the hush of a crowd that can't believe what it's seeing. It's in the sound of the sea, just over the dunes.

The local link As talented as they are unsung, indigenous musicians Mark Atkins (pictured) and Steve Pigram formed the local connection for the ACO's Gnaraloo residency. Atkins, 54, now lives near Tamworth but was born in Albany and grew up "near a swamp out the back of Perth". Perhaps best known for his didgeridoo playing, he also excels on guitar and has collaborated with Philip Glass and the London Philharmonic Orchestra and has performed at New York's Lincoln Centre. Pigram is from Broome, where he forms one seventh of the Pigram Brothers. "I've actually got nine brothers, but only six of them play in the band with me." His musicality is prodigious: he plays everything from acoustic guitar and requinto to harmonica, ukulele and dulcimer. "Doing this with Richard [Tognetti] is really a chance to showcase the majesty of Ningaloo," says Pigram, who also worked as musical director on Bran Nue Dae.

Pigram's music is about family, riverbeds and rainstorms - "nature, really". He worries that the same pro-mining mentality that waved through the $30 billion James Price Point gas plant on the Kimberley Coast could also threaten this part of Australia. "It's unique - it's desert meeting sea," he says. "It's about time we recognised that some things should not be touched." The Reef is a co-production of the ACO with Tura New Music. It will play at the Sydney Opera House on July 23. See aco.com.au. The writer travelled to Gnaraloo Station as a guest of the Australian Chamber Orchestra and Tura New Music.