It’s a scene of midsummer rock ‘n’ roll glory. As the unmistakably menacing guitar riff from Metallica’s “Enter Sandman” surges from towering PA stacks, a sweaty powder-keg of bodies packing the Bowery Ballroom explodes forward. Onstage a guitarist — blond, stripped to the waist, and clad in pink spandex pants — pops the top on a can of the alcoholic, caffeinated beverage Sparks, takes a swig, and sets the full can down, center stage. Head bowed, he explores the tempo of the Metallica song and loses himself in a series of savage full-arm downstrokes.

Then, in one of those maddening and inspired combinations of high wire ad-lib and premeditated stupidity that have kept rock ‘n’ roll alive and kicking for more than a half century, the guitarist strides cockily out into the spotlight, leaps into the air, and lands directly on top of the Sparks can — back first. An antifreeze-green colored sideways geyser of taurine, caffeine, and alcohol sprays across the stage as the can is crushed flat. With no time to spare, the guitarist, William Ocean, hops to his feet and dives off the stage, where he shreds maniacally atop the shoulders of the crowd whose collective mind he’s just blown.

It all happens in 60 seconds, and no one present is the least bit concerned that Mr. Ocean doesn’t have a guitar.

Welcome to the compulsory round of the 2006 U.S. Air Guitar Championships, where contestants like Mr. Ocean, Hot Lixx Hulahan (the defending national champion), and Bjorn Turoque (the ostensible star of the recent documentary “Air Guitar Nation” and the author of “To Air Is Human,” a book chronicling his experiences riding the phenomenon’s cresting wave), are much more than karaoke amateurs or the rock equivalent of civil war re-enactors.

Championship air guitar is a timed, judged, enthusiastically attended, and highly competitive combination of meticulous preparation, freewheeling ecstatic abandon, and poker-faced contrivance. At 60 seconds a performance, contestants achieve a perfect blend of parody and purity by stripping solo axemanship of its wanky self indulgence, and go-for-the-gold jock ambition of its arrogance.

“It’s not like the air guitar that everybody does in their bedroom,” the event’s co-founder, Kriston Rucker, said with some understatement.

Indeed, when Mr. Ocean (New York’s regional winner) and the rest of America’s regional champions meet tomorrow night at Irving Plaza to crown a 2007 national champion, a chance to “defend American honor in the world air guitar championships in Finland” will be at stake, according to Mr. Turoque. Tomorrow night, Mr. Turoque will act as “Master of Air-emonies” for the Official U.S. National Air Guitar Championships, a duty he also performed in 2006 and on a 15-city barnstorming bus tour that crossed America this past June en route to selecting this year’s finalists.

“What ‘official’ means,” Mr. Rucker said, “is that we are recognized by the World Air Guitar Championships in Finland, which I think was started in 1996.” Curious about what was then a predominately foreign phenomenon, Mr. Rucker attended the Finnish World Championships in 2002. “Many European countries, Australia, New Zealand were in it,” he said. “But it was strange and shocking and almost disturbing that the United States was not represented. We felt like it was the one global endeavor that the United States deserves to dominate, so we came back and started a national competition here.”

It didn’t take long for the sleeping U.S. Air Guitar giant to rouse itself.

“The very first year our champion won,” Mr. Rucker said. “The second year, our guy won but there was a judging controversy and we had to share the prize with New Zealand.” America hasn’t struck air gold since 2004. “We put them on notice and now we need to step it up,” Mr. Rucker said.

“Judging criteria is based on an Olympic figure skating scale of 4.0 to 6.0, handed down from the international Air Guitar governing body over in Finland,” Mr. Turoque said. A panel of judges assigns scores for each air guitarist’s two 60-second performances (a first-round song selected by the contestant and then a compulsory round in which the finalists interpret a surprise song selected by the event organizers) in three categories. At a minute apiece, “you’ve gotta be tight,” Mr. Rucker said. “I think that rule is one of the reasons why it works. If it were full songs, it would be excruciating.”

The first judging category is “technical merit,” which, Mr. Turoque said, “means not that you’re playing the right notes on a guitar, but that you’re playing the right notes on an air guitar.” The second is “stage presence.” Each contestant not only takes the stage without a band, but without an instrument. “That demands an ability to perform,” Mr. Rucker said.

Or, as Mr. Turoque put it, it’s a question of “how many faces do you melt? When I won New York in 2005, I wore a custom-made spandex unitard with zippered armbands in which I had placed dry ice so that there was a fog emitting from my arms,” he said. “That’s the kind of dedication we’re looking for.”

The final category is labeled “airness,” the textbook definition of which, Mr. Turoque said, is “the extent to which your air guitar performance exceeds the imitation of the real art form and becomes an art form in and of itself. That’s the most difficult to achieve.”

This year’s judging panel includes the author Malcolm Gladwell. “He’s going to be good at spotting airness,” Mr. Rucker said, “because he’s good at describing difficult-to-comprehend cultural concepts.”

Mr. Turoque predicts that tomorrow’s event at Irving Plaza will be the event’s best to date. Mr. Ocean, who arguably defined airness with last year’s Sparks-flattening back flip (viewable, as are most of these signature moves, by fan-posted videos on YouTube), was an audience favorite but lost to reigning champion Hot Lixx Hulahan on points.

“It left Ocean hungry,” Mr. Rucker said. “There are a lot of people who are definitely going to put on a good show. There are identical twins, one who won Dallas and the other who won Houston, and the guy from Chicago has a lot of airness.”

And America’s prospects for the world championships?

“In 2005, the world champion was a robot from Denmark, and then last year it was fat guy from Japan wearing a sweater with a tiger on it,” Mr. Turoque said dismissively. “Remember that an American won the hot dog eating championship this year after seven years or so of Japanese domination. I think that’s a good omen.”