Wacken, Germany  - As this year's festival starts in the northern German town of Wacken, Grandpa Willi is greeting out-of-town visitors with his trombone.

"What a day, what a wonderful day," he says, greeting the visitors between trombone blasts. On the side he sells homemade jams and juice. "It's a lot of work, but it's all natural," says the 89-year-old, who has been selling his wares here for seven summers to make sure the young concertgoers "get something healthy."

But one look at the small town's bank tower, decked out in black banners with a white bull's skull logo, or the average age of the visitors, and it quickly becomes clear that the out-of-towners are not in Wacken to hear Willi's trombone. Far from it.

Twenty years ago, this small town became the host of the Wacken Open Air (WOA), an annual heavy metal music festival that has hosted such acts as Saxon, Anthrax and Doro. Somehow, this small town of 1,800 residents has had no problem with the annual audio assault, which has grown to attract 75,000 guests from around the world at the end of every July.

"I like music, but this isn't really my style," says Willi as scores of fans with knapsacks and carts stream by, screaming "Waaaacken" and holding out their index fingers and pinkies in the universal metalhead salute. "I prefer German hits," Willi continues.

Indeed, for Willi and the village's other residents, the annual arrival of tens of thousands of metalheads is the best financial shot in the arm for their town, especially in the midst of a global financial crisis.

The show is traditionally opened by the Wacken Fire Fighters. Frontman Volker Vette is a picture of calm shortly before the concert's start, enjoying a beer in a local pub along the main street. Above him hangs a banner reading "Be glad. You're in Wacken."

"It's all good," says Vette, 69. He advises a long-haired, bare-chested metalhead to buy the newest album from the Fire Fighters. It's called "In the Beergarden."

What started out as a bit of beer-fuelled fun in 1990 as an open-air concert in a cow field has turned into the world's biggest heavy metal festival, drawing fans willing to pay 130 euros for a chance to see up to 90 bands. On average, 2,500 accredited journalists also attend.

It all costs about 8 million euros (11.4 million dollars). The town itself usually sells about 1 million euros in Wacken merchandise.

"There were 800 guests the first year. I played with my band and served beer on the side," says Thomas Jensen, who started WOA with his friend Holger Huebner and still organizes the event. The show is fairly crisis-proof, he says.

"For most visitors, this is a great distraction. They can really let off some steam here," he says as he drives over to the festival area, which is as large as 270 football pitches. His radio blasts out "Off to Waaaacken," by Tom Angelripper, a song the metal giant made especially for the festival.

Wacken's residents line up a few hundred metres as the fans show up, offering friendly good mornings and other wares.

"They're friendly people, they help me cross the street with my walker," says Elfriede Bolls, 73, of the fans as she sits in front of a bakery. "I personally like this Doro, the one with the long, blonde hair. I listen to that." And if the music gets too loud? "Oh, then I close the window."

The town's sidewalks are full of children transporting kegs of beer and tents to the concert grounds. A delivery from the bakery to the camping place costs 5 euros.

"The prices are stable. It costs the same as last year," says Sandra, one of the young entrepreneurs. Other residents have larger enterprises. Torsten Arp runs two beer gardens with space for 6,000 during the festival. In a given year, more than 100,000 litres of beer are served during the event.

The secret of the festival's success is that the whole village gets involved and welcomes it as a pleasant change of pace. After every show, Uwe Trede, a builder, organizes hundreds of helpers to collect 600 to 700 tonnes of trash. Similarly, several farmers are always ready to rent their meadows for the WOA.

Indeed, the yearly concerts are a boon to the community. They help support the kindergarten and the town's swimming pool would have closed long ago without the annual surge of metalheads who pay a combined 7,000 euros to use it.

Since last summer, the organizers have invested 600,000 euros into the festival grounds by installing sewage and improving power supply. All of that without ruining the meadows.

"After all, the surroundings provide the festival's charm," says Jensen. There are no plans to enlarge the festival. "Otherwise, we'll lose the special feeling we have here." (dpa)