Christmas season must be coming, because Mark Lazar has been fitted for his dress.

In the holiday spirit, attentive colleagues are watching Susan McKey try (and try and try) to bash her head with precision into a round wooden tabletop so the table, and not her head, splits in two and crashes to the floor. She finally does it - so convincingly it's almost shocking - and everyone laughs to celebrate her triumph, because laughter here is paramount.

On this recent Tuesday in Malvern, People's Light & Theatre Company is deep into rehearsals for its holiday panto - a zany, specialized British form of Christmastime entertainment that People's Light has cheerfully appropriated, and for which it arguably sets a professional American standard.

This year's holiday panto, Snow White, opened last night, the sixth in as many years and, like the others, an original musical with strong production values.

"It is insane to write a full-blown musical in 10 months," says Kathryn Petersen, who has scripted all of them in a speeded-up process anomalous for American musicals, which normally take three to five years to develop. "For all of us, what we're doing here is an amazing amount of work."

Creating pantos - the best are worldly wise and bawdy enough to amuse adults yet sufficiently harebrained and innocent to delight kids - is a demanding and "cool process, very collaborative," says Petersen. She says she researches stories such as Snow White, then spends a lot of time and energy figuring out how to honor both the tale and the subversive conventions of a panto. "As a playwright, it's been a gift. It's taught me a lot."

Long tradition

Though the full name for the species, which takes over British stages this time of year, is pantomime, it has nothing whatever to do with what we call pantomiming. Instead, it continues tradition with roots as far back as the Middle Ages - staged battles between good and evil that call for much audience hooting and hollering.

Pantos are performed sporadically in this country by professional companies, and by some amateur groups that focus on them. But as far as anyone knows, no other professional company has embraced the form as warmly as People's Light.

It's now a given that the 35-year-old company, which has a reputation for presenting theater on a high intellectual level, will break character once a year with merry mayhem - a musical with a guy in a dress who plays a brusque but woo-able woman, often with an actor who pops in as an animal, always with somebody evil, and inevitably with a messy stage free-for-all. (Snow White's is said to be the messiest yet.)

"It's not just children's theater. It's base humor and really funny, with situational things, and a lot of wordplay," says Pete Pryor, who directs Snow White and staged last year's Cinderella. "And ultimately you have to focus, and honor the story."

Do it right, and it's serious business, too. At this year's Barrymore Awards, the region's professional theater honors, Cinderella won as best musical, plus an award for Pryor as best director of a musical, one for original music (to Michael Ogborn, also this year's composer), and one to the whole cast for outstanding musical ensemble.

This for a form of stage entertainment some Brits don't even classify as theater.

You won't find the People's Light box office classifying it as anything but a whirlwind of revenue. By the time subscription tickets and walk-ins are tabulated, Snow White, with a budget of roughly $295,000, stands to take in about a half-million bucks.

So far, pantos have brought in a total of nearly $2 million, all the more impressive when you consider that five years ago, virtually no Philadelphian even knew what a panto was.

People's Light operates on the same income basis as any major professional regional theater: 40 percent comes from box office, the rest from contributions. But a robust holiday show can keep the year-round ticket tally from sliding, so arts organizations are always on the hunt for the next Nutcracker.

And on the way to finding its Nutcracker, People's Light discovered an entirely uncracked nut.

Seeking change

It's not that there was anything wrong with the company's musical version of Dickens' A Christmas Carol. The story is a holiday draw for plenty of theaters, and, as the millennium turned, it was People's Light's stalwart, too.

But a quirky thing happened at a People's Light summer festival of bare-bones productions in 2001: Gary Smith, the chief of epidemiology and public health at the University of Pennsylvania and active in local theater, showed Petersen a panto script he'd written.

Smith, equally conversant with the Veterinary Quarterly, the International Journal for Parasitology, and shows that feature men in dresses and people bashing one another, is a Brit who was introduced to pantos, he says, "at the age of 4. It was my first experience at the theater." (He's board chairman of Kennett Amateur Theatrical Society, a community stager of locally written pantos, this season Jan. 15 and 16 at Kennett High School.)

Smith is like the passenger who brings the alien seed to American soil on the sole of his shoe - although in his case it was intentional. His adaptation of the tale of Dick Whittington & His Cat was People's Light's summer panto, which played to enthusiastic audiences. Company artistic director Abigail Adams, who'd been looking for a Christmas Carol replacement, had found it.

Nowadays, she says, "people are starting to call in August for their panto tickets." At a theater in the English city of York, she says, "they go on sale in April, and they're sold out. That's our model."

Adams sent Petersen to Britain to research pantos, and dispatched Mark Lazar, who annually ends up as the "dame" - the guy in a dress. Smith wrote the music and lyrics to Sleeping Beauty, the first holiday panto, in 2004; Petersen wrote the script with Vince di Mura.

The company knew it had to educate an audience to enjoy - or even be able to define - pantos, and to provide the sometimes boisterous reaction the form solicits. This didn't take long. Beginning with the second one, 2005's Jack and the Beanstalk, audiences applauded Lazar in his womanly getup as soon as he appeared, before he uttered a syllable.

"I don't know who it says more about," the burly Lazar says - "People's Light, or the audience for putting up with it."

For a cast and crew, a panto is hard work; Snow White, which concerns a group of screwballs trying to film the story of Snow White, had a first reading, with show designers present, in June.

It's also fun. Three actors - Lazar, head-bashing McKey, and longtime company member Tom Teti - have been in all six pantos, and this will be actor Christopher Patrick Mullen's fifth.

"A panto is a great challenge," says David Bradley, who directed three of them. "It requires a combination of freedom on the part of the actors, but it also requires real precision among them. That's a beautiful kind of tension."

Watch Susan McKey head-butt that table in Snow White. You'll know what he means.

If You Go

Snow White will be performed through Jan. 3 by People's Light & Theatre Company, 39 Conestoga Rd., Malvern. Tickets are $28 to $53. For more information, call 610-644-3500 or visit www.peopleslight.org

Contact staff writer Howard Shapiro at 215-854-5727 or hshapiro@phillynews.com.