Talk about your bad hair days. On any other afternoon, Lancaster Avenue would be a parade of colors and noises, people and, most importantly, hairstyles. Today, as Gabrielle Revlock marches up the street, everyone she passes is bundled up in hats and hoods, shovelling. And when she finally jangles the door of her destination and greets the owner warmly, he laughs. "I hardly recognized you."

Revlock understands. In fact, part of her work finds her walking that treacherous line between what will and will not trip the memory switch. And all in the context of headgear. On the last Friday of January each year, she makes public her passion for wigs and promotes Wear Your Wig to Work Day (this year it's Jan. 28) as a 24-hour vacation from normality.

On this day, we've arrived at Freedom Wig Center near 40th and Lancaster to delve into the fun and fear of hairpieces. There, Revlock joins Krystyna Wiercioch and Martha Curren-Preis, who are both affiliated with WYWTW's organizing company, Mano/ Damno, and help her get the word out publicly about their atypical holiday.

As a dancer who recently performed with PIMA Group, Revlock explains the event in terms of acting. "Wigs bring up the issue of pretend versus real. It's true that a wig is not your natural hair, but so much of our appearance is constructed that if you're choosing your outfit, why shouldn't you choose your hair?"

Strolling the Freedom Wig Center aisles, where Revlock has brought Wiercioch to purchase one since "they have the best prices" locally, the wall of available styles almost begs you to imagine context. A jet-black bob of lacquered strands could grace a hip-hop backup singer. Flyaway blond wisps scream All My Children. They're splinters of scenes ready to be fleshed out. Mano/Damno's mission is to blur the line between art and life by making the public a participant rather than observer.

WYWTW Day was founded out of an ongoing photo project Revlock ran with collaborator Jennifer Shahade where they'd pose in wigs at abandoned Brooklyn swimming pools and a West Philly Wawa; it began three years ago with an annual celebratory party. This year's holiday has loosened up. Tomorrow will see Mano/Damno storming the streets, handing out free hair extensions, all donated or purchased out of Mano/Damno's coffers. "Everyone has the choice to become a performer," Revlock explains, "and casual encounters are the performance."

Powers of persuasion are required. As she pulls a gray, corrugated-crimp helmet wig from a shelf, Revlock considers the embarrassment people feel about unusual headwear. It's a challenge for people to step outside their comfort zones, and she says, "I can't make them do that." But she also wants to relax that uptightness for those who wear wigs all the time, either after chemo or because of premature or genetic baldness.

In short, we're laboring under a double-edged sensitivity to wigs: We think we can spot them but politely wouldn't let on to the wearer that we'd noticed. WYWTW flips that dynamic by encouraging most wig-wearing interactions to happen between friends, not strangers. Participants create "experiences for those individuals they encounter on that day and these will mostly be for those who know the "performers' and are familiar with their normal look." Wiercioch, a dancer who has performed alongside Revlock, plans to surprise the Bar Noir cabaret audience for her show this week by donning a flicked-out Katie Couric. Other Mano/Damno members — Kerry Kenny, Eric Botel-Barnard and Bonnie Friel — are preparing their Jan. 28 aliases, some completely believable, some unconventional.

As Curren-Preis peeps around the corner in white-blond tight curls, Revlock removes a fiery copper pixie cut. While some wig fans prefer the humor value of outlandish colors, Revlock is looking for something more lifelike. Store owner Danny Suh and manager Tenisha Wallace help her find a new favorite: a long, poker-straight two-toned style, dark to the chin, then strawberry blond to the ends. It's endlessly flickable and resembles a Toni & Guy dye job. Once a little addicted to dyeing, Revlock is now committed — or as committed as necessary — to the "immediately reversible" effect of donning wigs. Of the 30 she owns, several are showing their age, including a well-loved Annie cut which is shedding.

Standing under the wig wall, staring at all the styles, it's worth asking why we need a holiday to remind us that a change can do us good. "If everybody were to wear a wig," advises Revlock, "it would create an amazing visual — and the image would last for a day." That's a long time in wig world.

Wear Your Wig To Work Day, Fri., Jan. 28. For more information, visit www.manodamno.com.