"Ole!" "Muy bonita!" "Bravo!"

From the sidelines came shouts of encouragement and deafening clapping to a flamenco beat. On the floor, not in a cave in Granada but in a church basement in Arlington, skirts twirl, heels stamp, castanets click and a rose falls out of a dancer's hair as the 11 women and two men of Raquel Pena's intermediate flamenco dance class go through their paces and redobles and panaderos and fandangos.

This Spanish-style jam session is called a cuadro, which literally means picture or square, according to Pena, a slender dancer who started studying flamenco as a child in Spain and made her professional debut at age 16 at the Brooklyn Academy of Music.

"Flamenco really shouldn't be on a stage," says Pena. "This is more traditional -- people getting together and having a good time . . . well, at least we all finished together," she says to the class and begins more formal instruction.

"Let's start with the fandango . . . step, heel, redoble, heel, toe, kick -- but be careful that I don't get this. Point your foot immediately . . . I'm going to get the guitarists in."

The guitarists, whom Pena calls Carlos and Roberta but who are usually called Carlos and Bob, are students of Pena's husband, Fernando Sivent, who performs nightly with the Penas at El Tio Pepe.

"Flamenco is made up of rhythms," Pena explains to a visitor, "Within the rhythm -- which we call the compas -- there is improvisation. The guitarists can do as they like, the dancers can do as they like, and the singer -- as long as everybody is in the rhythm. You have to hear the rhythm -- it's like jazz . . . The guitarist will give you an entrance," she tells the students. "And at the end of his phrasing we'll do a redoble."

Palms twist gracefully and feet, clad in pumps with nails in the heels and toes, stamp in perfect rhythm.

"They are extremely dedicated," says Pena of the class. "For most of them this is only the second year of dancing, but they have already performed at folk festivals and charity events. The hardest part is the coordination of the castanets with the heel work. I try to teach it in such a way that they don't get bogged down."

The fandango is followed by an Alegrias de cadiz and a Mata la arana, in which 13 pairs of feet stomp mercilessly on an imaginary spider. After an hour and a half the students are tired but exhilarated.

"This is my weekly psychiatric something-or-other," says Gabriela Sendra, a World Bank employee who won't reveal her age but who used to think she was too old to dance flamenco. "I just let all the tensions go."

"I like the dignity and passion of it," says Marla Bush, changing out of a long, flounced skirt she made from a pattern supplied by Pena. Bush, a social worker, joined the class after seeing Pena's professional dance company perform at HUD. Mimi Clark, who works as an usher at the Kennedy Center, joined the class after seeing Pena gave a performance for children there. Yoko Sando, who taught dancing in Japan, sought but Pena when she came to Washington with her husband, a TV correspondent.

As the intermediates leave, Pena, who describes herself as "one of those people who have a lot of energy," works with a beginner's class on the sevillana.

"This is one os the first dances we larn," she explains. "It's the dance they do at the fair in Seville. Now change you weight -- get that knee right," she urges a beginner. "Toe, heel, toe, heel, walk, walk, walk, walk. Try and make it say something. It has to have character."

"She can make people who are klutzy at first look good after a few months," says Paula Brassfield, an advanced student watching from the sidelines. Brassfield studied under Pena's sister-in-law, the late Amor Sirvent. She now teaches dancing -- including a little famenco -- to kids.

Like the more advanced students, the beginners are a diverse group. Karen Hettinger, an opera singer, got interested in flamenco when she sang Carmen last year at Catholic University.

"I found I didn't know anything about flamenco," says Hettinger. "Next time I will."

As the class practices single stamps and double stamps, Pena sits down to gulp an orange drink and eat a piece of cheese. Without a break, she will spend the afternoon rehearsing her company of professional dancers and apprentices -- many of them graduates of her basic classes -- for a May 16 performance at the Kennedy Center. Already the company dancers are gathering on the sidelines, carrying rope-soled shoes to dance the jotas or humorous folk dances, ballet shoes to dance the 18th-century-style Spanish ballet, and nail-studded shoes to dance flamenco.

"Rock, like a rocking chair," Pena instructs a beginner, and then there is a short break during which student Janet Kiernan changes the cassette on her tape recorder.

"I tape these sessions so I can go home and review it," says Kiernan. "Flamenco is really an amazing feat of coordination. There's a wonderful fellowship here. I'm a computer programmer. I work with numbers. This is so refreshing -- it's a whole different way of thinking. I'm addicted!"