But aside from a few blips on the cultural radar, the simplistic formula and nothing-fancy attitude that defines garage rock has drifted to the fringes of musical history. Played in dingy garages and barrooms, it was mostly ignored by the mainstream.

Well, get your ear plugs ready.

That three-chord energy is set to shake the musical world’s hips as 40 bands from legendary rocker Bo Diddley to revivalists The Strokes gather in New York to kick out the jams at the Underground Garage Festival on Randalls Island in New York August 14.

“Look, we’ve been drowning in mediocrity for too long,” said Little Steven Van Zandt, who organized the festival and has championed all things garage for several years with a nationally syndicated radio show. “It’s time to re-embrace the basics, that spirit of rock ‘n’ roll.”

Every era of garage rock from the 1950s to the present day will be represented at Saturday’s festival. For some bands it will be the first time they have performed together in years. And in keeping with garage rock character, tickets are only $20.

Van Zandt says the festival means garage rock’s time has finally come. “It really is an international movement and right now is the time to recognize this officially as a genre,” said Van Zandt, Silvio Dante on HBO’s “The Sopranos” and the guitarist from Bruce Sprinsteen’s E Street Band. “We’re in a unique place that rock ‘n’ roll has been pushed underground and now it is being reborn.”

Despite its influence, defining garage rock has always been difficult, as it has constantly reinvented itself. But a few things have carried through: generally simple song structure, loud guitars and an attitude of rock-for-the-sake-of-rock.

“People sometimes mistake garage for kids playing out of tune,” Van Zandt said. “It’s that too, but there’s a certain spirit, a certain simplicity. There is a pop element to it, a certain ’60s pop structure. It’s the Stones at the Crawdaddy Club in 1962. It’s the Who at the Marquee Club. It’s a little bit hard to describe.”

Which perhaps explains why it has always played second or even third fiddle to easier to define genres like blues, heavy metal or hip-hop. But it’s garage’s outsider status that has always branded it as cool, said Fabrizio Moretti, drummer for The Strokes.

“Even though the mainstream doesn’t recognize garage as much or as prevalently as those crazy huge bands, garage does get the privilege of being looked upon as something that’s cool even by people that don’t understand it,” he said.

And when the mainstream has grown tired of some of its mainstay pop formulas, it has always looked to garage for an adrenaline shot of hipness.

“Every once and a while there’s a point where mainstream and garage kind of cross,” Moretti said. “Joey Ramone said they had modeled their stuff after ’50s pop songs, so there you go.”

A wide variety of bands from different eras will come together next weekend: not just Bo Diddley and Iggy and the Stooges, but Nancy Sinatra, the Dictators, the Fuzztones and the Romantics.

Such contemporary acts as the Strokes and The Mooney Suzuki round out the bill.

But the festival’s highlight no doubt will be the first U.S. appearance in nearly 30 years of the New York Dolls – whose cross-dressing proto-glam/punk approach was tremendously influential on the development of punk and new wave.

Singer David Johansen (who later recreated himself as pompadoured R&B singer Buster Poindexter) said he’s not sure if the Dolls really quite represent garage.

“We were more like a storefront band than a garage band. But most bands start out in some sort of dump,” he joked.

Regardless, the 54-year-old Johansen said he and the band’s other surviving member, guitarist Syl Slyvain are prepared to play just like they did at 1973’s Halloween Ball at the Waldorf-Astoria.

“Don’t worry, we’ll be tarted up good and proper for a bunch of old queens,” he said.