Halcyon Days. A growing group of dance devotees is bringing back to life not only forgotten dances that were once favorites, but the whole flavor of life that went with them.

THE dancers dip and glide around the dance floor, hands resting just so on shoulder or waist. Ladies wear 19th-century ball gowns, men are attired in white tie and tails. It is all as proper and Victorian as one could wish. You should have seen them the night before, though. As the first notes of the tango started, backs stiffened, chins went up, and you could practically see the steam rise.

It's not many places that one can get dolled up in hoop skirts one night and flapper fringe the next, all the while dancing to a live orchestra. But one place is a vintage dance, a revival of 19th-century and ragtime-era dances. The 100 dancers here at Concord's old Scout House came to a workshop, Halcyon Days, to learn more about these dances - and to kick up their heels.

The workshop was presided over by a latter-day Vernon and Irene Castle (a popular dance team in 1913), Richard Powers and his fianc'ee, Melanie Cougarstar.

Participants in the five-day workshop took daytime classes in dance etiquette, couple dances of the Victorian ballroom, quadrilles, and early set dances. At night they unpacked their grand attire and attended a Ragtime Trot and a Victorian Soir'ee, then wrapped it up with a Bal Masque.

Mr. Powers, a dance historian and teacher from Cincinnati, is spearheading a modest revival of vintage dance. Since he started teaching six years ago, the pace has quickened. He taught for 10 weeks at various dance camps last summer. He's just come from a sold-out weekend in Washington, D.C. And he'll be leading workshops in Atlanta; Baltimore; Knoxville, Tenn.; and Philadelphia this month and early in February. He's one of a small group of devotees around the country promoting these dances of grandparents' days.

In addition to teaching, Powers leads the Flying Cloud Vintage Dance Troupe, which graced some of the ballroom scenes on the ABC-TV miniseries ``North and South'' last year. The troupe has just finished a new PBS show, ``Mrs. Perkins' Ball.'' There are other performing troupes in New Haven, Conn.; Boston; Los Angeles; and Philadelphia.

The popularity of vintage dance can be explained partly by the charisma of Powers and Miss Cougarstar, a nursing student and his teaching partner. With their precision, delight in each other, and electrifying intensity, the pair bring the dances to life.

But the attraction is more than personality. Richard Castner, a teacher of historical dance at the State University of New York, at Brockport, was on busman's holiday at Halcyon Days. Between dances, he said that the revival in this type of dancing taps into the ``interest in old-fashioned clothing and nostalgia'' going on these days. ``Richard's hit a period that seems to strike a responsive chord,'' he said.

Watching Powers and Cougarstar dance at a Fourth of July celebration last summer struck a chord with Elliot and Vivianne Pierce, dancers from Kensington, Md. Since then, the Pierces have attended three workshops. They enjoy the challenge of learning new steps, and something else: the people, who range in age from 13 to 74. ``There are all diversities of backgrounds,'' says Mr. Pierce, ``but almost without exception they are all very kind, thoughtful, active, intelligent - all the things you like to have in your friends.''

The dances include the waltz, polka, schottische, galop, and quadrille of the Victorian era, and the tango, one-step, and a whole menagerie of ``animal'' dances from the ragtime era, including the bunny hug, turkey trot, and camel walk. Powers, who never danced until he was 27, got involved in dance through his love of Renaissance music and his interest in international folk dances and contra dances (couple dances done in lines).

Since 1980, he's been teaching workshops, digging up old dance manuals, and learning the history of the eras.

``We try to approach these dances and perform them in the context in which they were originally done,'' he says. ``Dances which may seem tame today but were shocking back then should not be done in a silly way. We should try and catch the original risqu'e element.

The ladies often make their dresses themselves from historical patterns; the men hunt in vintage stores for their dapper duds. For the workshops, though, they need practical clothes. The all-day sessions are hard work, the dance steps as intricate as those rapped out in ``A Chorus Line.'' ``Step-swing-step, and hold,'' Powers calls out. ``Then, one-two-step-corte-step-together-three-step-slide-close.'' His dancers may look a mite perplexed, but they don't look at their feet.

They're learning more than just steps: They're steeped in the etiquette as well. The mores of the Victorian era, says Powers, were based on selflessness, doing what you could for the pleasure of others (see box at right).

The vintage-dance revival is coming at a time when Miss Manners's newspaper column is syndicated nationally and parents are sending their children to etiquette school. Mr. Castner says, ``We've had two generations of permissive upbringing. It may be now that people are reaching back to older rules to see if they work.''

It's also coming at a time when swing dancing is hot stuff, and hotels are having tea dances like crazy. Powers acknowledges that vintage dance might be a fad. ``Social dancing seems to be an endless series of fads. They generally live a very short life, except for the 19th-century waltz, polka, and schottishe, [which lasted] for perhaps a generation. Disco, and going back through swing and earlier, most of these were fads that lasted about five years.''

``We're hoping not to achieve too big a splash right now, so that it can endure for a while, just as contradancing and international folk dancing have.''

Even if it is a fad, the Halcyon Days participants look as if they could dance forever. The dances ``are very romantic,'' says Casey Carey, of Cambridge, Mass. ``Doing them - when you do them right and your partner is doing them right - is like flying.''

For more details, contact the Flying Cloud Academy of Vintage Dance, 3623 Herschel Ave., Cincinnati, OH 45208; (513) 321-4878.