There is nothing quite so energizing, yet at the same time so comforting, as the sight and sound of a crackerjack company of folk dancers and musicians. While you sit there marveling at the sweep and speed and technical feats, you're also lulled by the symmetry of the formations, the innocence and sense of community, the joviality and simplicity of it all. Safe within this theatrical utopia, you're temporarily freed from worries about the tensions of the modern world.

The two greatest folk troupes in the Soviet Union -- the Moiseyev Dance Company from Moscow and Virsky's Ukrainian State Dance Company -- produce these effects more powerfully than any other ensemble of their sort performing today. In fall 1986, Washingtonians made their way through metal detectors to experience the highly stylized fusion of ballet and folk dance that is the Moiseyev trademark. Tuesday through Thursday, the Virsky troupe brings its inimitable blend of pyrotechnics and delicacy to DAR Constitution Hall, midway through a 14-city tour that has so far been greeted with sold-out houses and rave reviews.

It has been 16 years since the Ukrainians performed in the United States. Company founder and choreographic master Pavel Virsky died in 1975; a whole new generation of dancers has come of age. Yet, with a few exceptions, the dances -- and the spirit of the enterprise -- remain constant.

"Having been handed such a legacy, there is a necessity to preserve it," says Miroslav Vantukh, who has served as company director since 1980. "I have the utmost respect for Mr. Virsky. He was the greatest connoisseur of folk and classical dance. But in our country we have a saying: 'Traditions are only alive when they're developed.' I have not turned the company into a museum. All of our dances are based on Ukrainian folk traditions, and they are not frozen. They keep changing."

Vantukh's task has not been an easy one. Following an artistic legend demands both confidence and a certain degree of self-effacement; Vantukh seems to possess just enough of each.

"Being an artist, I have my own vision, and I try to incorporate that vision into my own choreography," he explains, speaking through an interpreter in a telephone interview. "Yet when I work at my own dances, I always have in mind that Virsky's style should be maintained."

How does that translate into movement? Without straying from the male dancers' brilliant air turns, split-jumps, barrel turns and sustained squats, or the female dancers' precision footwork, he has devised several pieces that have been described as slicker and faster, with more technique than his predecessor's. In Vantukh's "Povzumets" or "The Crawl," for instance, the men remain in a squatting position for six minutes, all the while engaging in a fierce contest of flexibility and double-jointedness that has been referred to as "ancient breakdancing."

This male bravura style, always a company hallmark, is currently being played to the maximum. "This program for the U.S. emphasizes the men," Vantukh concedes. "A lot of male dancers were chosen by the impresarios who arranged the tour. Naturally, males have more athletic ability, but that does not mean that our company bases its repertory on male abilities alone."

Ukrainian tradition holds that women should be regarded as beautiful ornaments; hence the women's dances are soft, lyrical and earthbound -- chain dances and pattern dances performed by young women in narrow skirts.

Vantukh himself never danced with the Virsky company. Born in 1939 near Lvov, he studied Ukrainian folk arts -- dance and music in particular ("We love music!" he exclaims when asked to identify any distinctly Ukrainian traits. "We're a singing nation"). After a short stint teaching, he was drafted into the Soviet army, during which time he danced in an amateur performing unit.

On his return to civilian life, he continued to teach and, at 23, founded his own troupe. He called it Yunost or Youth Company. Semiprofessional, specializing in specific regional dances of the Ukraine, the group traveled all over the world and won Vantukh the title of Merited Artist of the Ukraine.

Yet Yunost existed in the shadow of the renowned Virsky ensemble, which was started in 1951. Vantukh met with Virsky fairly frequently, accepted his advice and consulted him at times. But in the 18 years that he maintained his troupe, Vantukh remained independent creatively. When asked about his artistic influences, he does cite Virsky, but then reels off a list that also includes Igor Moiseyev, Marius Petipa, Yuri Grigorovich and other pillars of Russian culture.

Today, Vantukh not only heads the Virsky, but also oversees the company school. "Almost all our dancers graduate from the Choreography School of Kiev," he explains. "Then they come to us. We don't accept beginners -- only youngsters who have been dancing from eight to 10 years in amateur groups and really show promise." Many of those dancers are members of the same family: Currently the company boasts a mother-daughter duo, twin brothers and several husband-and-wife teams.

Although the Ukrainian dancers have been lauded during each of their four visits to this country, they have never achieved the name recognition accorded the Moiseyev ensemble. Is it because the Moiseyev appeared here first? Or that its tours have been more frequent? And is there a rivalry between the two groups, a relationship akin to that between the Kirov and Bolshoi ballets?

"In a narrow sense, there should be artistic rivalries between all of the performing ensembles," says Vantukh. "It is a real stimulus for creative activity. Virsky and Moiseyev were choreographers of the same generation ... so a rivalry is only natural.

"But our companies differ in the choice of repertory," he says. "Moiseyev interprets dances of the world, while Virsky based his company only on Ukrainian dancing. As far as the Moiseyev popularity, I would attribute it to the fact that they have just visited the United States more often."

Vantukh himself seems to be having a fine time here. He says his company enjoyed a warm reception during its two-week run in New York. Asked whether glasnost has affected his endeavors in any way, he acknowledges that the troupe's current tour may have come about as a result of the thaw in Soviet-American relations.

"This thaw," he adds, "was brought about by the whole world, not just our two nations. It could hardly affect my art, but I certainly appreciate it, like everyone else in the Soviet Union.

"Surely our spirit, our mood was affected. It will no doubt have a positive influence. A widening of cultural exchange -- when nations will share each other's art -- will enrich every man of arts and letters."