OULU, Finland (AP) — In a sweaty, dark, clubhouse in northern Finland, people were jerking, jumping and screaming into the early hours Friday while moving their fingers with precision through the air.

To the sound of blasting rock music, they were battling it out for a spot in the final of a competition now in its 20th year: The Air Guitar World Championships.

What started off as a joke has turned into an annual fest of crazy mime artists who compete for the title of World Air Guitar champion in the city of Oulu, a high-tech hub on the Baltic Sea surrounded by forests.

In 1996, there were eight competitors with one foreign champion, from neighboring Sweden. This year, a record 30 so-called "dark horses" from a dozen countries competed for a place in the final to join seven national champions from as far away as the United States, Japan and Canada who automatically go into the final with reigning world champion, Japan's Nanami "Seven Seas" Nagura who won last year at the age of 18.

Only 6/10th of a point separated the first and last of the nine who qualified for the evening's competition to make a total 17 finalists.

Beth "CindAirella" Melin from the United States, in a ripped pink tank top enthused the packed crowd with air punches and kicks that sent her baggy black miniskirt flapping, egged on by shouts of "wow" and "yeah." Her performance convinced the jury of a fourth place, behind two compatriots and Russia's Kereel "Your Daddy" Blumenkrants.

The high temperature was too much for 2002 champion Zac Munro from London, who pulled his shirt off to whistles and whoops from female spectators, as he wrapped up his solo riff to earn him the seventh spot.

The final later Friday will be a cooler affair, held on an outdoor stage in a central city square dampened by steady rain.

One of the judges, Aline Westphal from Germany, said she will be looking for precision.

"It's important that the contestants are very precise on the instrument and their facial expressions too," she said.

And, of course, the inexplicable "airness" quality needs to be good, she added. "You just feel it when airness is there."

Eyes will also be on Matt "Airistotle" Burns from Staten Island, New York, the three-time title holder in the U.S. — the "powerhouse of air" which holds dozens of air guitar competitions every year that have provided a living for some. They include the official "Air host" of the world championships, Dan Crane, who lives in Los Angeles.

Author of "To Air is Human: One Man's Quest to Become the World's Greatest Air Guitarist," he has never made it to No. 1 but finished second twice. He decided to stay in the rarified "air world," hosting the world championships since 2008.

"The absurdity required to hold this event in this small city in northern Finland is equally proportionate to the absurdity of playing an invisible guitar in front of thousands of people," Crane said before the evening's contest.

Belgium's national champion Emmanuelle "Miss Issippy" Stempniakowski, admits she has butterflies ahead of the final.

"I will give all I have inside me — all the adrenalin, all the joy and all the happiness," she said baring her teeth in a cat's growl.