London — For an audience, classical ballet is beautiful but often mysterious. How does a ballerina dance on her toes? How do male dancers hold and lift their partners without any seeming effort?
In an era where dance is reaching out to wider audiences, some companies are trying to unveil such mysteries. One of these, the London Festival Ballet, is taking the technicalities of dance from behind the footlights and into school halls, museums, and community centers across England.
A lanky young man in white crumpled shorts and a T-shirt that sported a ''J.R.'' (''Dallas'') motif scrunched up his bare toes and looked puzzled. The instructions were given again: ''You're in third position -- feet turned out. We'll do three petits retires and a plie. Preparation . . . arm -- one-two . . . .''
J.R. grabbed the makeshift barre (a blue-painted radiator) and tried again. This time he managed to slide his foot up to his knee and down again, but he had trouble with the plies. He kept bending as the others around him were straightening up.
But the others were having their own troubles as they grappled with the ballet steps: nurses, bank cashiers, secretaries, shop assistants, technicians, and students dressed in a motley collection of sweat pants, tights, shorts, and leotards.
For most of them it was their first taste of ballet. They were all members of an adult education drama class at the Addison Institute in Hammersmith, South London. Their teachers for this one-time 21/2-hour class came from the stage of the London Festival Ballet Company.
In charge was former Festival Ballet soloist John Travis, in red sweat pants and a navy top. He has been one of the leaders in a two-year-old effort by the company to take classical dance outside the theater in educational programs aimed at wider audiences.
The programs were set up by the company's marketing department in March 1980, originally offering a ''day of dance'' to teachers and students in the London area.
By the end of the year, nearly 10,000 people all over England had seen the presentation. During the past two years, the program has expanded to include a summer school for gifted children, a six-week adult education class, open rehearsals and ballet classes for Friends of Festival Ballet. The ballet also conducts weekend programs that include visits backstage, meetings with dancers, ballet classes, and watching the company perform.
Mr. Travis, curly haired and cheerful, takes his team (himself, two dancers from the company, and a pianist) to lecture and demonstrate at regular schools, women's institute meetings, libraries, sports complexes, and dance centers.
In an interview before the Hammersmith class began, Mr. Travis said, ''We stress that this is a workshop and not just a chance to see a pas de deux up close.
''There are enough myths about classical dance that we have to break down. We want to make ballet more accessible to a greater public, unwrap those myths, widen the scope of the dancers, and educate the audiences, making them critically appreciative.
''It's nerve-racking for the team with such close contact. But there is immediate feedback, more than in a theater, where dancers are further away.''
When J.R. and his classmates arrived at the Hammersmith auditorium, they found Mr. Travis and dancers Anne Manger and Nigel Burgoine setting up a portable barre and laying out costumes for ''Romeo and Juliet.'' Dancer Stephen Long was pianist for the evening.
The class perched on small school chairs in three rows not more than 10 feet from the team. The dancers briefly described how they became interested in ballet, then showed a quick version of every dancer's daily warmup exercises using the ''potted bar.''
''Remember, the stage should be your friend in supporting you,'' Mr. Travis said. ''The Festival Ballet has had many painful experiences with uneven, nonsprung floors on tour, and now we take our own floor with us everywhere.''
After the barre work, Anne and Nigel slipped on flame-and-green costumes over their practice clothes and rehearsed part of the balcony scene from the Rudolph Nureyev version of Romeo and Juliet.
They showed the class what could happen if they were not exact in their timing and spacing. Anne tried an arabesque starting too close to Nigel, and hit him with a leg. Nigel picked her up but did not grasp her firmly enough at the waist; his arms slid up under hers and suddenly she was too heavy to lift. Anne tried some leaps into Nigel's arms without first scaling down the steps to fit the small stage. Result: a tangle of arms and legs.
For 15 minutes the pair rehearsed a section of the balcony scene pas de deux, repeating it four times. John Travis explained that the class had just seen preparation for only one minute of the pas de deux, which itself lasted 10 minutes - in a ballet of three hours.
Stephen Long came off his piano stool to show the character-dance side of ballet, and demonstrated the flag-dance and sword fighting he does in Romeo and Juliet, moving and twisting with enormous energy and gusto.
Nigel held Anne aloft, and she fell into the ''fish dive'' position, arms wide. The class was astonished that she could keep her position without holding on, since Nigel's arms were also held out. Mr. Travis said, ''We'll do it again, but this time they will have their backs to you.'' And the class learned yet another secret of the ballet world.
A short break, and the class began exercising. Giggles and moans and scores of embarrassed looks followed as people discovered that it wasn't easy. Even the simple exercises weren't simple.
Concentration on the legs meant that arms were forgotten. They grew longer and stiffer, until John Travis teased the class by likening stiff fingers to ''bunches of bananas.'' Posteriors stuck out at an angle during plies. Mr. Travis sternly forbade ''dive bombing'' during the port de bras; as people tried to go down slowly they groaned aloud with the effort. It was hard to feel demi-points through sneakers.
Exhausted and flushed, one young woman in the class said, ''I hadn't realized how many little things in ballet are important to achieve the overall effect. . . . I am puffed out, and we've only been dancing steps for about half an hour. How they dance on stage for hours I can't imagine . . . how dedicated they must be.''
John Travis and the team adapt the basic two-and-a-half-hour program to different audiences. When they visit schools, they tie their presentation to current productions. The children are sometimes able to attend special matinees to watch for the points they have seen demonstrated, such as the one-minute section of the pas de deux, the flag dance and the sword fighting.
The success of the educational program is thanks to the enthusiasm with which John Travis and his team set out to make ballet more widely known.