IN 1979, WHEN MICHAEL SMUIN brought his San Francisco Ballet to Salt Lake City to dance his choreography of "Romeo and Juliet," it seemed unlikely that this production would ever be seen here in any other guise. Like most artistic directors who choreograph, Smuin was protective of his works, which gave his company a distinctive image.

But nine years later Ballet West is producing its own version of the work, staged by Smuin to Prokofiev's luscious score.

"Romeo and Juliet" will open the 1988-89 season at the Capitol Theater with six performances, nightly at 7:30 (note earlier curtain time this year) on Sept. 21-24 and 26, plus a 2 p.m. matinee on Sept. 24.

Much water has flowed under the bridge for Smuin since 1979, including his resignation from SFB in 1985. An escalating career in freelance choreography for film, television and stage culminated last June in his winning a Tony for best choreography in the Broadway revival of Cole Porter's "Anything Goes," and he has other choreographic projects booked far ahead.

But 10 years ago, "Romeo and Juliet" was a big success for him and his company. He staged the pas de deux in 1975, and the complete ballet without scenery in 1976. "By the next year my board was shamed into providing scenery," laughed the talented choreographer.

Dance in America took note of the ballet, and filmed it for public television in Nashville in 1978 _ the first full-length ballet they had done. SFB toured the country with "Romeo and Juliet," and it was danced as recently as 1987 in San Francisco. "I feel I have come full circle by bringing it here," said Smuin.

Since his resignation from San Francisco Ballet, he retains rights to his more than 30 choreographies for that company, and hopes to set some of the others on interested companies as time goes by.

Yet he still believes in the necessity of a distinctive character for a dance company, and worries a little about the homogenization that results from traveling choreographers and productions, emphasis on the classics, and the influence of screen, theater, symphony and opera - "cross-fertilization of disciplines," as he calls it.

"Truly, I dreaded going through the growing pains of this ballet again, starting it from scratch," said Smuin, a small, energetic man with a quick wit and friendly, open manner.

"But when I got here last summer, I found that 90 percent of the spade work had been done in the three weeks before, by my wife Paula Tracy, and by Diana Weber and Attila Ficzere from my original cast. Paula has a photographic memory; she can remember dances she did when she was 6 years old! I rely on her to be my memory. I guess the secret of our 26-year marriage is that we are not only lovers, but pals and business partners.

"I was especially concerned about the sword fights, which are fast and intricate, and dangerous, and must be staged to the last inch so no one gets hurt. When I conceived the work, I wanted the Act I street fight to be a spontaneous brawl. But the Act II fight must be intense, for blood.

"I turned to Steven White, who has done sword fights for many stage productions and motion pictures. He has worked with Ballet West on fencing since the first of the summer, and the fights are now precise and up to tempo."

What is the essence of Smuin's `Romeo and Juliet," what distinguishes it from other versions such as Cranko's or MacMillan's?

"The essence is speed," he replied instantly. "The play took place in only four days, there is this great sense of urgency. The story is about love at first sight, and precipitous action. I relate to the Zefferelli film with its terrific pace, but seamless continuity.

"But as I worked with Prokofiev's exciting score, I found great chunks of music that made no sense in context, and I soon discovered that they had been written in to accommodate scene changes. So I sought ways to make quick scene shifts, sometimes without bringing the curtain down, and eliminate those stretches that disrupt the flow. For example, we get from the ballroom to the balcony in one minute and 33 seconds, give or take a few seconds. And in the third act we telescope much of the action into one scene, through brief, telling pantomimes."

Smuin also has highlighted the drama in secondary characters such as Mercutio, Benvolio, and Lady Capulet, whose liaison with Tybalt, only alluded to in the play, he makes much of. "Her grief at Tybalt's death is much more than that of an aunt," he said.

He finds Prokofiev's music not only beautiful, "but a real labor of love, in which you sense a great intellect at work. The music fits the action so perfectly that some of the time you can almost imagine that Shakespeare's lines are like lyrics, superimposed over it," he said. Hard as it is to believe now, when the score first came out in 1938 it sounded dissonant and harsh to contemporary ears, and the premiere was danced in Czechoslovakia, not Russia.

Smuin deplores ballet as just steps. "That's boring," he said. "Ballet is theater; and the word for theater in Greek was at one time a verb."

*** "ROMEO AND JULIET" serves to introduce to Salt Lake City the exciting new principal dancers, Daniela Buson and Marcello Angelini, who come to Ballet West most recently from the Cincinnati Ballet. The husband and wife duo bring a dimension of Italianate freedom and depth of emotion to a partnership that began in their native Italy, at almost as early an age as the immortal couple they portray.

They met when each was 17, as new members of the Teatro Communale in Florence, Italy. A year later Angelini was awarded a scholarship to study at the Kiev Institute of Dance in the USSR, with the pre-eminent Denisienko.

In October 1982 Buson and Angelini were awarded first prize in the pas de deux section of the Rome International Competition, and the Golden Rose at Milan for the most promising young Italian couple. Before joining Cincinnati Ballet, the two spent a year as soloists with the Deutsche Opera Ballet in Berlin, and were principals with the Northern Ballet Theatre of Manchester, England.

As they unfolded the story of the making of international soloists - in excellent English, with flashes of temperament and charm - one noted the presence of important teachers along the way, who spent enough time with them to shape and direct their course.

Daniela Buson was born in Palermo, Sicily, where at age eight she began her training at the Academy of the Palermo Opera. "I was not too happy there, so after two years I went to the private Jacques Beltrane School, where I advanced much faster," she said. At 17 she received a scholarship to study in Reggio Emilia with an excellent teacher, but had only been there a month when she was invited to join the ballet in Florence.

"I wanted to stay and study, but my father urged me to take the job, he said I should get on with my career," said Daniela.

Marcello Angelini was born in Naples, where his father danced with the San Carlo Opera Ballet. He too began studies at eight years of age, in the state-run San Carlo Opera School; but after five and a half years he was "retired," "because the director said I would never be a dancer," said the handsome danseur, whose face reflects a constant play of emotions.

"My father worked with me for three and a half years, then I was invited to join the Florence Ballet. My year in Kiev was wonderful. The company is Russia's third in importance, with 300 dancers. Mikhail Baryshnikov began his serious studies there. I worked a great deal with the best teacher, in a class of all Russian boys. At the Kirov or Bolshoi, foreign boys do not receive such attention."

Buson and Angelini credit much of their success to working with the artistic director at Florence, Evgeny Polyakov. "He was like a father to us, so generous with his time, he coached us sometimes three hours a day," said Buson. "He would find us places to perform our pas de deux before we had to debut them in the house." After three years in Florence, they left when Polyakov left. He is now assistant director to Rudolf Nureyev at the Paris Opera Ballet.

The couple always had in the back of their minds the desire to try the United States, and when artistic director Robert De Warren left the Northern Ballet to go to La Scala, they made the leap. They had six offers to join U.S. companies, but chose Cincinnati because of artistic director Ivan Nagy, whose elegance as a dancer is legendary.

Nagy accepted them on the strength of a videotape rather than a live audition, and he has taken an interest in coaching Angelini. They still have 11 weeks of contract to fulfill with Cincinnati Ballet, and have guested or will guest with the Ballet of Basel, Switzerland, Palermo Opera House Ballet and Ballet Arizona.

They made the change to Ballet West, one of the companies that originally offered them contracts, because of the repertory they will dance, and better working facilities. "Cincinnati Ballet is jammed into the Conservatory," Daniela explained, "and practice studios almost disappear when school is in session. Here you have an incredible theater."

They are favorably impressed with Salt Lake City, find American free enterprise stimulating, and do not regret leaving Italy with its subsidized arts and lifelong ballet contracts. "Many fine dancers emerge in the Italian companies, but many become complacent," said Angelini. "American dancers are hungry, and work harder in general."

Both acknowledge a long-held dream to dance Romeo and Juliet, and have high ideals for their characterization.

"Juliet is very difficult because she is so young, but you must not be a giddy little girl, you must be yourself," said Daniela.

Besides mastering the intricate fights, Marcello must make other accommodations to Smuin's version. "I see Romeo as a loving boy, yet he consorts with a harlot," he said. "It's hard to encompass both concepts."

Angelini wants perfection, not just to be a "kind of nice" dancer. He feels that "after you have accumulated your vocabulary, you must have something to say, and say it in a way that is right for you. A coach can tell you what to do, but finally it comes down to you and what you can do out there."

"Romeo and Juliet" will be conducted by Ballet West's new music director, Terence Kern, who will lead an orchestra of freelance musicians in the absence of the striking Utah Symphony. Alternating with Buson and Angelini in the title roles will be Rhonda Lee and Raymond Van Mason, Jane Wood and Robert Arbogast. Joseph Woelfel, Miguel Garcia and Jiang Qi will dance Mercutio, and Bruce Caldwell and Charles Flachs, Tybalt.

Tickets ranging from $6 to $36 are now on sale at the Capitol Theater, 50 W. Second South, 533-5555, or at any Smith'sTix location. Students are $4, senior citizens and groups may be discounted. Season tickets, at a savings of up to 24 percent, are on sale through Sept. 26.