If ever there was a day that went to 11, Friday would be it: the 11th day of November, the 11th month, in the year 2011.

And that is why for more than a year now, fans of the movie This Is Spinal Tap have had Friday circled on their calendars. There has even been a social media movement to have the day declared Nigel Tufnel Day, named for the Spinal Tap character who claimed that his guitar amplifier could go to 11, when most axe men could turn theirs up to only 10.

It happened during a scene in the 1984 faux documentary mocking the life of an aging British heavy metal band in which Nigel, played by comedian Christopher Guest, was showing filmmaker Marty DiBergi, played by actor and filmmaker Rob Reiner, his guitar collection. The stash included a Gibson Les Paul with sustain so endless Tufnel thought it could be heard long after it had been played. Another guitar he forbade DiBergi to even look at or breathe on.

Then, Tufnel showed DiBergi the amazing feature of his Marshall amplifier: "If you see, the numbers all go to 11," Tufnel says.

"Does that mean it's louder?" DiBergi asks.

Tufnel responds, "Well, it's one louder, isn't it?"

"That's what guitar players always want: They always want more," says Brandon Bowlds, an online salesman for Wilcutt Guitar Shop in Lexington. "They're never really satisfied with anything in terms of their equipment. They want it to rock a little harder, if you could just get a little more out of it."

And that was the essence of that joke, Bowlds says.

"Guitar players are always modifying things and saying, 'Oh, look at this. I just had my amp customized," says Lexington guitarist Steve Broderson, who plays with the Twiggenburys, an all-British rock cover band that has a regular gig on the first Friday night of each month at The Pub at The Plaza at Fayette Mall. "There's always the gear freak in the band that's always tweaking his amp and saying, 'Doesn't that sound a lot better?" and everyone else is saying, 'Yeah, sure. I'm glad you spent $3,000 on that.'"

Broderson, whose band played a Spinal Tap tribute show last weekend at The Pub and who is having a private 11-11-11 party Friday, says that's what made This Is Spinal Tap great: It so concisely mocked absurdities of rock 'n' roll life: the inner-band squabbles over things like album titles and cover art, and the egos and pretentiousness and silliness, such as the band getting lost trying to find the stage door in a cavernous arena.

And then there's the guitar player who wanted to go "one louder."

In the movie, DiBergi asks Tufnel, "Why don't you just make 10 a little louder and make 10 be the top number, and make that a little louder?"

Tufnel pauses and says, "These go to 11."

These days, it's not hard to find amplifiers that go to 11, 12 and higher numbers. Then there are amps that don't have any numbers on their volume and tone-control knobs.

The Wilcutt staffers say there are many factors that can go into how loud an amplifier is besides the numbers on the dials.

All 10s are not created equal, Web salesman Eric Cummins says, nor would all 11s be the same.

"There are different wattages of amps," and wattage is the key indicator of an amp's power, he says. There are other controls, including gain, which creates distortion, and volume-boosting foot pedals. The quality of the cable that goes from the guitar to the amp also is a factor.

"Every little thing you do, from the quality of the cable to the pickups and things that generate additional current to give you a little bit more," Wilcutt owner Bob Wilcutt says.

But Broderson says some gear makers have gotten in on the joke. There's a Digidesign guitar multi-effects processor called the Eleven. It costs nearly $900, and Broderson is not rushing out to buy one. He says his amplifier goes only to 10.

"I am happy with my 10," he says. "At the sound check, we just ask for everything to be just a little louder than everything else, and we're all just fine."

Deep in his guitarist's heart, though, he'd probably like to be able to crank it up to 11, and Friday would be the perfect day to do it.