WATERTOWN - In the Revels' headquarters here, a plaster pre-Columbian head sits on a desk, rakishly topped with a velvet jester's cap. It's an odd juxtaposition of cultures and eras: one Mexican, the other medieval English. But it's just the kind of cultural inclusivity that Revels has become famous for in its three decades of music making.

Christmas Revels, which opens tonight for a two-week run at Sanders Theatre, is an annual music and dance extravaganza that celebrates the winter solstice through the lens of other cultures. Around since the '70s, Revels has grown from a grass-roots organization run out of founder John Langstaff's home in Lexington to a national powerhouse overseeing 82 productions in 12 cities. The brainy Birkenstock types who've run the place for years have adopted a corporate lexicon, using words such as ''quality control,'' ''product,'' and ''brand'' without flinching. It's just another step in the organization's ongoing dance of progress. For executive director Gayle Rich, artistic director Patrick Swanson, music director George Emlen, and director of marketing Alan Casso, Revels isn't just a show, it's a passion.

The show's loyal audiences, some 200 volunteers, and 80-member cast would seem to agree. Still, first-timers should prepare to be a bit perplexed. You'll think you've been transported to 18th-century Armenia and Georgia - the Revels' focus for this year. You'll be surrounded by the lush costumes, festive dances, music, and stories from that region. Then, suddenly, an ancient British tradition will make an appearance. Men will dance with ribbons tied to their legs. Other men will prance around wearing antlers. Then, just before intermission, everyone - performers and audience alike - will dance into the lobby, holding hands and singing something called ''The Lord of the Dance.'' Like most everything else in Revels, the song combines several cultural elements. ''It's a Shaker tune and a poem with Christian imagery in a secular setting,'' says Swanson. ''The performers and audience formally come together in the great, vaulted Gothic [lobby] space and join in a long, serpentine line dance until it fills up.'' Just don't call it a conga line. The dance comes from the 17th-century court of Louis XIV. ''You see a transformative effect,'' says Swanson. ''The audience comes back from that in a completely different mood; they're readier to sing.''

Audience singalong? Dancing in the lobby with strangers? Maybe you'd expect something like this to happen in funky Cambridge. But in Evanston, Ill.? In Houston? Yikes.

What are these Revels? A yearning for tradition Langstaff, an author and musician, started Revels in 1971 to promote the understanding and appreciation of traditional folk music, dance, and rituals from around the world. Now director emeritus, Langstaff actually mounted an early incarnation of Revels in the 1950s when he was a concert baritone in New York. He had in mind a musical event that combined a celebration of the winter solstice with the medieval British rituals he'd loved since he was a boy, among them the Abbots Bromley Horn Dance, a hunters' dance of good luck, and the mummers' play, a folk play about death and rebirth. He produced his first Revels at Town Hall in New York in 1956. ''I didn't have two pennies to rub together,'' Langstaff says. ''I remember schlepping stuff around and got friends who were actors to do the mummers' play.'' With no money to advertise, he filled only half the house. In 1966, Langstaff included Revels elements in an NBC production. He also wove it into his teaching at the Shady Hill School in Cambridge.

But he didn't do another full-scale Revels until 1971, when urged to do so by his daughter and Harvard offered Sanders Theatre for free. The show was a hit, and it became an annual event. Revels started with medieval or Renaissance themes, then moved into Celtic and Victorian. Driven by Langstaff's voracious interest in musical and cultural traditions of other lands and times, the group branched out. Soon it was performing traditional dances and music from Renaissance Italy, 19th-century Appalachia, Mexico, and Scandinavia. ''People have a submerged yearning for tradition and ritual,'' he says. ''Revels answers that for them.''

The Armenian and Georgian folk traditions that are this year's theme will be told through the eyes of an actor playing Sayat Nova, an 18th-century Armenian troubadour. In the loose story line, Sayat Nova is invited to the court of the king of Georgia. In keeping with the Revels' tradition of having authentic musicians and dancers, performers will include the Ararat Chorus, the Arev Armenian Folk Ensemble, and the Nor Serund Dancers. Another crucial element for Langstaff was the sense of community the show embodies. ''I wanted people to get involved, like family,'' he says.

Some audience members have come for years and now bring their grandchildren. A few of the younger cast members have practically grown up on the Revels' stage. The huge cast - of professionals and novices - is chosen anew each year. ''You see a professional production, but the people in it often are not,'' says Rich, who's been with the group since 1977. ''It's very important to us.''

An expanding empire

From its shoestring beginnings, Revels Inc., the nonprofit organization that runs the Christmas Revels and the Spring Revels (added in 1974), now has a budget of $1.3 million. Revels Records has released 19 CDs. Revels Publishing has produced three songbooks, a series of choral arrangements, and a line of educational videos and teacher training supplies. As popular as it is in some circles, Revels is not for all tastes. Some can't get used to the mix of professionals and untrained actors. Others may feel that seeing one Abbots Bromley Horn Dance is enough. But others, particularly those who want to introduce their children to other cultures and participatory musical events, are intensely loyal.

Spinoffs were inevitable. In 1975, Langstaff's daughter Carol started a Revels in Hanover, N.H. New York and Washington, D.C., soon followed. Others were started by people who had experienced Revels in other cities and missed them. The newest, in Boulder, Colo., is just a year old. ''We don't want to go out and `seed' new cities,'' says Langstaff. ''People have got to come to us.''

Starting a Revels is not for the fainthearted. Rich says up to two years of planning is needed before the first performance. ''It takes tremendous personal commitment; you have to be driven,'' she says. ''When someone expresses an interest, I send them a daunting packet of material. Usually we don't hear back.'' After she sent the packet to a woman in Boulder, Rich received a letter back, saying: ''I'll bet you thought that would scare me away. I still want to do it.'' The satellite Revels operate independently but under the watchful eyes of the Cambridge Revels, which wants to maintain the respect for traditions and the commitment to excellence that are part of John Langstaff's vision. The new Revels choose their programs from ones that Cambridge has already done. Revels Inc. provides scripts, technical assistance, and advice. ''We look at what cities have done in the past, what resources each community has to offer,'' says Rich. ''Some may have more Hispanics, some more Irish. Washington and Oakland have done terrific African-American Revels. That would be harder to do in more homogenous Hanover.'' Swanson, Emlen, and Rich review videos and tapes of other shows and field many urgent calls. ''We get the show on here, then zip around the country seeing as many of the others as we can,'' says Swanson. ''We try to make sure there's a live body seeing each one.''

The demand for new Revels groups grew so great, in fact, that the Cambridge team has yanked the cord, at least for a while. Canada, Australia, and England have expressed interest in forming their own Revels, but the logistical demands are too great. The existing 12 are all the small staff can manage, says Swanson.

In his decades with Revels, Langstaff has done just about everything in the show. Though he officially retired in 1995, he stays involved with small projects and keeps coming up with new themes. ''I'd like to do one based on women,'' he says. ''Not women exclusively, of course. But this would be a real ritual, not new age-y and fake.'' Still, the biggest thrill for him remains helping nurture groups of people. ''I'm going to talk to the chorus in New Hampshire,'' he says. ''I'll ask them, `How many people are here for the first time?' Hands will go up. Then I'll say, `You're the ones I'm most interested in. You're probably asking yourselves, is this going to work? Can we pull it together?' They're going to get such a charge.''

Christmas Revels opens tonight at Sanders Theatre and runs through Dec. 29. Tickets are available through the Harvard Box Office at Holyoke Center Arcade in Harvard Square, by phone at 617-496-2222, or online at www.fas.harvard.edu/ tickets.

Catherine Foster can be reached at foster@globe.com. This story ran on page E15 of the Boston Globe on 12/13/2002.
© Copyright 2002 Globe Newspaper Company.