Yet just a few weeks before the first note is played, energy levels and optimism in the Clockenflap office-hive are high, if not intense. Hell, this year there's even a chance of breaking even for the first time. In fact, this is their best year yet, says Sweeting, with conviction.

"Hong Kong has never seen a festival of this scale or scope before - a way of completely escaping the city and becoming immersed in new experiences," he says.

Make your way into an arty, concrete-floored little office on Hillier Street, Sheung Wan, and you'll find a small crew, often perched on or around a meeting table. They may be rifling through scraps of multicoloured armbands, discussing the merits of M&M-filled cake, negotiating projector-screen prices or going over the programme for the film tent. They are overseen placidly by the mounted head of a deer called Janet and backstopped by a plush sofa in a side room, for the nights when they don't make it home.

First, there are the big three - the trio of electronic music enthusiasts (all British - although Sweeting was born and raised in Hong Kong) who bonded in the late 1990s and helped to produce Rockit, Clockenflap's annual but short-lived predecessor. Music man Sweeting, now managing director, is responsible for disseminating the Clockenflap word from his base in London and booking the acts; Forster manages visual and creative direction, as well as office morale - being stationed there much of the time; Mike Hill balances the financial and legal side of things with the running of his IT firm.

Around this core a paid team has sprung up - including three other full-timers and five contracted for the peak months - to complement and co-ordinate an army of outside consultants. Three are Cantonese-speaking locals, a couple are old friends and contacts of the three founders, and a few - a young Canadian producer, a British event manager known as Grandma and a Hong Kong-Australian who oversees the film tent - were recent lucky finds. What unites them is a connection to Hong Kong, a love of independent art and music and a willingness to work themselves into early graves for it.

"We all have strong personalities, but we work hard and we compromise," says Kinny Barlow, brand sponsorship manager. "It's a pretty organic process for those who don't, in terms of being screened out."

The vibe of the office is perhaps more businesslike than might be expected, although lightened by indie wardrobes, the occasional blast of music and liberal use of the word "gubbins" (along with other less printable catchphrases). With the event looming, many metaphorical plates are being spun and organising the festival is the most stressful thing many of them have done.

"We shout sometimes, dance, go for a ciggie - the usual stress busters," says Barlow, who has worked with the team from the beginning but took on her first full-time role last year. "The stress makes us closer. But coming out of a Clockenflap does feel a bit like coming back from the frontline. It feels weird, surfacing back in the real world."

- Forster, producer Urgyan Mueller and art curator Aidan Li - are heading to the site. It's an unusually hot October day and the West Kowloon plot is a mass of scruffy green, its iconic backdrop paled by haze. Although there's little to see, logistical issues are tackled, things measured, site plans prodded.

"We've got into trouble before by going overboard with our sketches on paper, and departing a bit from reality," says Forster. "These visits prevent it from feeling too abstract."

They are here primarily to meet members of a Fo Tan art and design collective, 430, who have responded to the call for proposals for an installation. The artists - whose plans include a giant head that reacts to people's facial expressions and a video screen that responds to touch - are on site to try and figure out what is viable.

"Hong Kong artists aren't used to working outdoors, or on this kind of scale," says 430 creative director Told To. "The biggest installation we've done before is in a shopping mall, so for this project we have much more to consider, including wind and rain."

The festival has always had an art focus but this is the first time Forster has been able to build a dedicated curated area. It's part of a plan hatched with Li - who last year produced Hong Kong's newest art and design festival, Detour - to both showcase and encourage local creativity. Yet this has taken some work.

"Firstly, there's not much communication between artists and design groups based in different districts, such as Fo Tan and Kwun Tong," says Li. "So this has been sometimes challenging to co-ordinate. And then there's finding the artists who are comfortable working with this huge space, and giving the guidance they need to create viable festival works that respond to our brief - and are safe, cheap and good quality." This has involved bringing the more fanciful projects down to earth and in line with official requirements. Some proposals would have gone way over the heads of audiences, says Li. And some, adds Forster, just didn't make sense: "One guy wanted to dig a six-metre pit. Never mind that there's a tunnel running under the site."

Among the ideas chosen are a drawing-machine workshop, a noise-making see-saw and various (bicycle-powered) contraptions designed by Hong Kong artists for festival-goers to amuse themselves with.

"Clockenflap provides good venues, resources and an audience, so it builds a good link between the art and an audience. And they give us freedom; Hong Kong artists rarely get to think big, think freely," says To. "We do commercial art because we need to, but this for us is pure art."

misconceptions he'd like to address. As Clockenflap's music weathervane for five years, as well as being mana-ging director for its umbrella company, Proper Job, he is used to fielding liberal advice on who he should book.

"It's not only the most heated debate in the office usually, but everyone else I know has an opinion, too," he says. "They say, 'Why not invite this or that band?'" But it's not that easy, he says. "Booking is a convoluted process that comes down to people, relationships and loyalty."

These relationships have been forged with agents, managers and bands during the course of Sweeting's 15-year career in the industry, which includes booking throughout Asia for promoting company Untitled Entertainment and others, through Proper Job. But there's also a need to fit in with touring schedules and album cycles, and to convince bands that the region is a lucrative ground for live music.

"Each date we book, we're competing with every other venue in the world," he says. "But we've seen a growing demand in Southeast Asia that's now making it a viable place to tour."

Every increase in capacity and earning power brings higher-profile artists within reach. Clockenflap may not have the chops for the Rolling Stones, but it has an iconic location and a legacy, both of which have helped deliver it the likes of Primal Scream and Azealia Banks.

"One of the nice things is the buzz about Clockenflap," says event manager Matt Jones. "It's a bit of a trailblazer and is getting a name for itself now. I speak to friends in England who have heard of it; even my brother in America says people know of it."

"We are entering a really lovely position," says Sweeting. "Agents know us, artists are spreading the word and so some are coming to us. The key is to then pick names that are relevant."

And get the timing right. Last year, he managed to book British indie-rock band Alt-J well before their Mercury Prize nomination, and English sensation Bastille just before they released a No1 album. The 1975, another British indie-rock quartet, were among the first acts he booked this year, says Sweeting, who managed to get in before the hype surrounding their debut album swelled.

But what is "relevant"? Sweeting acknowledges that across the region audiences have different personalities and predilections. But, born and bred in Hong Kong, he credits a sixth sense for allowing him to give local festival-goers what they want - and what they don't yet know they want.

"When we're programming a festival, it's about balance," he says. "We need headline names that will sell tickets and get you standing arm-in-arm with someone you don't know, singing the lyrics to the same song. But I'd argue that the main joy of the festival is discovering people - those you have yet to fall in love with; those who are amazing but might not sell tickets. Those are the ones you remember."

Sweeting 's excitement for this year's line-up is tangible, despite an initially lukewarm public response when the headliners were announced. Due to perform are American rock band Black Rebel Motorcycle Club, thanks to a dialogue, he says, that started years ago, while veteran musician and producer Nile Rodgers, with his band Chic, is going to "blow the roof off", even though Sweeting admits the choice was a little "out of left field".

"It's a bit like De La Soul last year," he says. "I know in my bones that this is something that will really, really work."

Electronic dance music and the "father of Chinese rock music", Cui Jian, are also key draws this year. "Daytime concerts give you room to be eclectic, and we are definitely that," he says. "But, in a nutshell, I'd say we book slightly left-of-centre: artists that are accessible, with an independent spirit."

Sweeting has also used the festival as a platform for emerging local talent. More than half the bands who perform are based in Hong Kong, and the event has boosted acts such as Chochukmo, who last year migrated to the main stage, and Noughts and Exes, who have been on a similar trajectory.

"We're just one piece of the puzzle," says Sweeting. "But both of them have managed to keep on the rise, releasing records and holding solo shows at bigger and bigger venues. The day we have a truly local band headlining our main stage will be a really proud day."

"The acts [Sweeting's] bringing in from outside - some of the best - are helping to take Hong Kong music out of the box," says project co-ordinator Ivy Yuen, a former flight attendant who now sports cropped silver hair and open relief at her career switch.

"It's new for Hong Kong," says the team's graphic designer, Jianchi "Nono" Chen. "It shows people that, for those who want it, there's more to music than our pop music scene."

So, dare we mention BloHK Party? The three founders admit to being crestfallen a few months back when they found out that the electronic and hip hop-flavoured one-day festival, curated by American rapper and producer Pharrell Williams, had been scheduled for the Saturday after Clockenflap, at the same venue. They would have hoped for a more savvy programming approach by the West Kowloon management team, for the benefit of both events. Indeed, as Forster observes in a glum moment, they had looked on course to breaking even - or better - on ticket sales this time, before BloHK Party appeared on the horizon.

Nevertheless, says Sweeting, choosing his words carefully, it is good for Hong Kong to have choice, and competition will give Clockenflap the chance to strengthen its identity.

"We have so many points of differentiation," he says. "We're not simply an outdoor party, and we don't really conform to a 'VIP' vibe. We're about showcasing Hong Kong at its creative, independently spirited best."

Adds Forster: "And it has forced us to get our act together in terms of promotion."

This last point is critical. One of the biggest challenges for organisers in Hong Kong over the years has been spreading the message about open-air festivals - what they are and what they can offer. For Jones, in his second year working with the city's bureaucracy, this has been a particular problem. Being in charge of pulling together permissions, licensing and safety certifications; of co-ordinating food vendors; and of liaising with the police and fire departments (both of which, he says, have been extremely helpful), he has found government departments unsure about how to approach the event.

"I got a list of questions last year that seemed more appropriate for an indoor concert," he says. "But as an open site, things like exits and fire safety are very different. We've been working on it, though. It's just a case of making them aware of the different needs of an outdoor festival."

But public uncertainty is more problematic. Barlow, a Cantonese-speaking native, says she has found it hard to promote Clockenflap to two very different audiences - the Western, internationally minded and the local.

"Hong Kong people will spend plenty of money for a concert [over a few hours], but they don't like to commit all their weekend - it's to do with being hardworking," she says. "It is also hard to get across that we are more than just a long concert - we are arts, culture, atmosphere and for everyone."

But that, say the organisers, is what makes it all worthwhile in the face of damage-limitation strategies and risk assessments; field-strimming and crowd-control plans; food and beverage licence negotiations and the need to reduce, where possible, opportunities for lethal accidents. The three and their team have taken on the spirit of pioneers: encouraging and educating people and co-ordinating a space for musicians and artists to collaborate on a large, open scale - all in a city that's not quite sure how to do that.

"We Hongkongers can see things in a very planned style and can live in a bit of a box but, at Clockenflap, you let it go a bit," says Barlow. "Helping to make that happen in my hometown - to help people experience a new cultural opportunity - makes me feel like I'm doing something worthwhile."

That feeling doesn't take full effect the moment the music kicks in, though; everyone on the team talks almost reverently about the "Sunday high" - when they wake up on the final day and the fires are mostly out, the crises handled and the plans followed more or less to the blueprint.

"You bump into people on the site who you know and it's nice, because they don't see what we are dealing with, and haven't noticed what might have been stressing us out," says Jones. "They're just having a great time. And you're like, 'It's working - we pulled it off!'"