STARTING OUT on the street may be tough, but it's the ultimate challenge -- for the actor, that is. Mime and magic, juggling, acrobatics and witty patter must attract an audience from crowds of people who have somewhere else to go.

Veteran street performer Michael Frith regards the street as the best training ground for actors. And so, as a result of his classes in street theater, students 10 to 15 become performers of magic and mime, and jugglers of pins and balls. Some wear top hats and balance chairs on their limbs, others do somersaults and flips. Through it all there's a constant patter of jokes and smalltalk.

"Street performing is in a sense the actor's fertilizer," says Frith, who is co-teaching classes in street theater this summer through Round House Theater and the Smithsonian Resident Associates. "It's a way to invest and begin to nurture the joy of performing and love of audience contact at an early age.

"The student has to learn to move and speak equally well; to literally think on one's feet. For instance, we warm up at the beginning of class by saying rapid-fire tongue-twisters while doing calesthenics. We also work on learning to walk on stilts, handstands, flips, using imagination in elaborate ways. These exercises, especially juggling, free the student to use both sides of the brain."

Frith also says that learning the skills of a street performer at a young age is beneficial because it builds confidence. "We do one exercise in which the student 'auditions" before an 'agent' (the rest of the class). The class critiques the performance. It gives the students a chance to be honest but not cruel and allows them to learn what makes a good performance."

The goal of the classes is for the student to create his or her own street persona. Students are especially attracted to the top hat persona, says Frith, who taught a course last year through Round House Theater. Many of the boys choose to dress in tuxedos and perform balancing acts with canes and chairs. Three of his students created a trio -- sort of a clown version of the Andrews Sisters -- and encouraged the audience to sing the fourth part of doo-wop songs.

"This is the new vaudeville," says Frith, "The street persona is in a sense a universal clown. In class, we encourage the students to identify the clown in them."

On the street, Frith becomes Ace Backwards: a dyslexic clown who often performs in reverse, as well as performing acrobatics, juggling, comedy and mime.

"I'm a reformed dyslexic, and while I was working to overcome my dyslexia, I became interested in the process by which we acquire education. My street persona tries to stimulate the audience's imagination and explores the process of learning."

Street performers have gained such popularity that shopping centers and plazas are built with areas designed specifically for them. Performers regularly appear in Baltimore's Inner Harbor. Washington street performers are rarer than in Boston, San Francisco or New Orleans, where street performing's a tradition. Frith says Ace Backwards is asked to appear at such places as the Old Post Office Pavilion, the Crowne Plaza Hotel in Rockville and in Chinatown during its New Year's celebration.

But Frith pointed out that magicians and musicians are beginning to appear with some regularity at downtown Metro stops.

"Street performing is related to the trend toward a more visually-oriented society," said Frith. The length of a street act is four to six minutes -- the length of time between commercials on television. Afterword, the street performer usually engages the audience in some kind of participatory activity, much as a commercial does, he says.

What's the difference between a street performer and a clown?

Frith says that a street performer uses less makeup and is more interested in drawing the audience to him rather than brashly going after them. Street performers are less aggressive, explains Frith, and it usually takes them a while to draw a crowd.

"It's pure, raw theater," he says. "It's the skill of the performer that entertains the crowd, without any high-tech gadgets."

Frith will be teaching the Junk 'n' Jive Street Theater class with Paul Hadfield, a Ringling Bros. graduate; at the Smithsonian, the class will be taught by Frith and Bernie Collins, with a special appearance by mime Mark Jaster. JUNK 'N JIVE STREET THEATER -- Round House Theater Summer Program. Learn juggling, slapstick, breakdancing, street mime, plate spinning, magic tricks and jive. Ages 10 to 12. July 6 to 24 from 1 to 3:30 p.m. or 9 to 11:30 a.m. July 27 to August 14 from 1 to 3:30 p.m. or 9 to 11:30 a.m. Bethesda and Silver Spring locations. $110. 468-4172. STREET THEATER -- Students learn about jesters, jugglers, magicians, musicians, mimes, dancers, acrobats and clowns and create their own street persona. Ages 12 to 15. Smithsonian Summer Camp through Smithsonian Resident Associates. July 6 to 17. $180 to $220. 9:30 a.m. to 12:30 p.m. 357-3030.OTHER CLASSES

For more traditional classes in the performing arts, many summer programs are offered for children of all ages. The classes become more intensive and professional for teen-agers, with several requiring auditions.

AGES 4 to 6 CREATIVE DRAMA, MUSIC & DANCE WORKSHOP -- Gives boys and girls experience in the combination of drama, music and dance. June 29 to July 3 from 4:30 to 5:30 p.m. and August 3 to 7, 10:30 to 11:30 a.m. $30. Arlington Center for Dance, Adams Square Mall, 2401 Columbia Pike. 920-4340. ENTER AND EXPLORE -- An actress and an artist help children create drama based on arts exhibits. Ages 5 to 7. August 3 to 7; 9:30 am. to 12:30 p.m. Smithsonian Young Associates. $90 to $110. 357-3030. KINDER-STARS -- Children's Theater of Arlington. Reenacting tall tales, exploring folklore and customs, songs, games, dances, clowning, radio and TV skits, puppets and costumes. Ages 5 to 6. June 22 to July 3. 9 a.m. to noon. $45. Nottingham School. 739-2903.

AGES 7 to 11 DANCE CAMP -- Bethesda YMCA. Three weeks of jazz, ballet and modern dance plus creative movement, makeup and masks. Ages 8 to 11. June 29 to July 17. 9 a.m. to 12:30 p.m. ($150 to $170) or 9 a.m. to 4 p.m. ($225 to $250). Ayrlawn Center. 530-3725.

ROUND HOUSE THEATER ARTS DAY PROGRAM -- Introduction to music, crafts, theater, graphic arts, mime and improvisation with each student selecting a specialty project in either pottery, puppetry, story theater or junk 'n jive theater. Ages 6 to 11. July 6 to 17; July 20 to 31; and August 3 to 14. 9:30 a.m. to 2:30 p.m. $110. Bethesda and Silver Spring locations. 468-4172. THEATER IN A SHOEBOX -- Children's Theater of Arlington. Children learn improvisation, pantomime, movement, music and puppetry through selected stories, folklore and myths. Sets created in a shoebox and costumes designed with crayons and paper. Ages 7 to 9. June 22 to July 3. 9 a.m. to noon. $45. Nottingham School. 739-2903.

AGES 8-14 DRAMA CAMP -- Bethesda YMCA: Improvisation, mime, puppetry, Reader's Theater, memorization within a drama setting. Ages 8 to 14. July 20 to August 7. $225 to $250. 9 to 4. Ayrlawn Program Center. 530-3725. DUKE ELLINGTON SCHOOL OF THE ARTS -- East of the River Community Arts Program. Anne Beers Elementary School. Ages 7 to 12. 282-0093. FINE ARTS CAMP -- Prince George's Community College. Work with professionals in drawing and painting, drama, photography, creative movement, crafts and music. Ages 9 to 12. Largo campus. July 20-24. 8:30 a.m. to 3:30 p.m. $85. 322-0882.

AGES 10-15 FOLLOWSPOT THEATER CAMP -- Intensive three-week performing arts camp that includes supervision in acting, improvisation, scene study, music, dance and movement, puppetry and playwriting. Ages 10 to 15. Fairfax County Department of Recreation and Community Services. July 6 to July 14. 9 a.m. to 3 p.m. Jackson Intermediate School in Falls Church. $150. 691-2671. STAGE DOOR -- Children's Theater of Arlington. Intensive three-week theater arts program in acting/directing, dance, improvisation, music, voice/oral interpretation, movement, technical theater and performance. Ages 10 to 14. Gunston Arts Center. July 6-24. 10 to 4. $150. 739-2903.

AGES 10-18

ACT III -- Children's Theater of Arlington. Intensive four-week session of classes and rehearsals that culminates in a student-produced musical. Auditions on June 15 and 16. June 29 to July 24. 10 to 4. $185. Gunston Arts Center. 534-1487. ACTING TECHNIQUE FOR YOUNG PEOPLE I -- Studio Theater. Theater games, vocal and movement exercises, as well as pantomime and improvisation. Ages 10 to 13. Auditions this Saturday, classes June 15 to August 3, Tuesday and Friday from 2 to 4 p.m. $295. 232-7267. ACTING TECHNIQUE FOR YOUNG PEOPLE II -- Studio Theater. Designed to develop students' basic acting skills, the activities focus on characterization, use of text and subtext, as well as ensemble work. Ages 14 to 17. Auditions are this Saturday. Classes are June 15 to August 3, Monday and Thursday from 2 to 4 p.m. $295. 232-7267.

FINE ARTS CAMP --

Performing Arts Emphasis. Prince George's Community College. Hands-on experience in the college's television production studio. Activities include TV production, drama, improvisation, creative movement and music workshops. Ages 12 to 15. July 20-24. 8:30 a.m. to 3:30 p.m. $85. Largo campus. 322-0882.

LIVING STAGE WORKSHOP --

Ages 13 to 18. Arena Stage. See description under ages 6 to 12. Mondays and Wednesdays or Tuesdays and Thursdays from 12:30 to 3:30 p.m. $235. 554-9066.

SUMMERTIME WITH SHAKESPEARE --

Learn about Shakespeare and his times, including Elizabethan dancing, courtly manners and costumes, calligraphy, medieval arts and crafts. Performance of "The Taming of the Shrew" concludes program. Ages 10 to 18. Sponsored by Fairfax County Recreation Department. Irving Intermediate School in Springfield. July 7 to July 18; 9 a.m. to 3 p.m. $80 tuition; $20 supplies. 691-2672.

TEEN ACTING WORKSHOP --

Round House Theater. Teens are introduced to the thinking mind, body and spirit of the actor. Ages 12 to 17. July 6 to August 14. 9 a.m. to noon. $168. 468-4172.

TEEN PERFORMANCE ENSEMBLE --

Round House Theater. The ensemble will create an original theater piece using scripted materials, group improvisations and music . Ages 13 to 17. July 6 to August 14. 1 to 4 p.m. $168. 468-4172.