Dark Mofo festival is changing the way Australia's southernmost capital is being seen and enjoyed, by locals and tourists alike.

The 10-day event, which thrives on being more than a little out there, kicked off on Friday with a fresh array of avant-garde performers, public art and experiences on offer.

Like its creator the Museum of Old and New Art, Dark Mofo has thrived on an improbably successful recipe - selling the obscure, the weird and the conceptual to the masses.

In its third year, Dark Mofo is once again poised to put a fire in the belly of mid-winter Hobart, right when and where it is needed most.

At the heart of this year's incarnation is a monstrous, flame-throwing musical instrument called the Fire Organ.

Commissioned especially for Dark Mofo, this musical beast breathes columns of fire and hammers out an ear-punching beat that sounds like an orchestra of backfiring jalopies.

The boisterous Fire Organ will take pride of place in Dark Park - aka the Macquarie Point precinct - creating a booming soundscape that is as much felt as heard and seen.

The mechanical, pyrotechnic sound machine will be played by Dutch artist Bastiaan Maris by way of a keyboard.

Dark Mofo executive producer Kate Gould explained how the "auditory experience" worked.

"Gas is pumped through the pipes and they're lit ,so you see fire jets coming out the top and then this mad Dutchman actually plays them like an organ," she said.

"He manipulates the volume of gas through the pipes."

Keeping it fresh, and weird, the key to Mofo success

This kind of extraordinary, sensory public art experience epitomises what Dark Mofo organisers aim to deliver, for free.

Creative director Leigh Carmichael says Dark Mofo is all about celebrating Hobart. ( ABC News: Gregor Salmon )

While there are many ticketed items on the program, Dark Mofo creative director Leigh Carmichael said oversized public art was the very core of Dark Mofo.

"When I first presented the idea to [MONA founder] David Walsh of doing a winter festival he said, 'Well, if we're going to do another festival - because we had MONA FOMA in summer - then go and have a look at large-scale public art projects around the world. That's the only space we're not playing in at the moment.'"

Running with the idea, Mr Carmichael made uniqueness Dark Mofo's currency - keeping things fresh, however weird.

"To push into new territory - that's where it's at," he said.

"We pride ourselves on trying to find new ground and that's hard.

"Every time you do something new like the Fire Organ you've got to go through a whole new process but I think that's what keeps it exciting."

A unique celebration of, and for, Hobart

Hobart's roundabout fountain turns red for Dark Mofo. ( ABC News: Gregor Salmon )

While many may think Dark Mofo is purely bait for artsy mainlanders, the festival from the outset aimed to get locals to revel in their city's character.

"We've got the tourists in mind but it's really centred around what it means to be Hobart, celebrating our weather, our environment, our city," Mr Carmichael said.

"Those are things that really matter.

"This needs to be a community celebration."

The Winter Feast, extended to five nights, has proven to be one of the most popular events, putting a bacchanalian twist on Tasmania's food forte.

Last year 45,000 people took a pew at the communal tables and this year's 65 stall holders are expected to be feeding 20,000 mouths a night.

The city has gotten into the spirit, most visually by lighting up buildings and monuments in red for the duration of the festival.

But with around 130,000 people attending each of the first two Dark Mofo festivals, the event's appeal has reached far beyond Tasmania.

As Dark Mofo's principal sponsor, State Growth Department has injected $1 million per year towards the staging of the first three festivals.

Events Tasmania director Adam Sproule said part of the event's "resounding success" as an investment was the interest it had roused interstate.

"[Darl Mofo] is designed to make the city an integrated part of the festival, to attract festival-goers from throughout Tasmania, and to become a key destination for artists and visitors from interstate and overseas."

To that end, he said last year about 20 per cent of tickets for the various shows and events on the Dark Mofo program were interstate purchases.

He said it was estimated 3,500 interstate and international visitors travelled to Tasmania for the festival in 2014.

Dark Mofo breaks tourism rut

Dark Mofo takes place during the winter solstice. ( Supplied: MONA/Remi Chauvin )

Pivoted, pagan-style, around the winter solstice, Dark Mofo has inflated a perennial flat patch in Hobart visitation numbers, breaking interstate resistance to flying south come winter.

Steve Old, general manager of the Tasmanian Hospitality Association, said the festival had delivered a "massive increase" in bookings since it began.

"Only a couple of years ago, when Dark Mofo started, our occupancy stats show we had a six per cent occupancy rate increase around the state and also a three per cent rise in Hobart," he said.

"That's a massive increase for a particular month.

"We're talking thousands of bed nights."

Mr Old said the benefits spilled over to the city's eateries and bars.

Luke Martin from the Tasmanian Tourism Council said while some visitors were courted with free flights and cheap accommodation, the flow-on effects of the influx boosted the bottom line of businesses at a time that used to be an off-season rut.

"It's a bit of a stunt but ultimately it's about getting people to switch on and say, 'What is this event?'," he said.

"What a great incentive to get down to Tassie in what would otherwise be a time of year where you would look anywhere but Tassie in terms of a short break stay."

No doubt some of those visitors will be taking part arguably the most hard-core event on the calendar - taking a nude swim in the River Derwent to celebrate the passing of the longest night of the year.