How do you prepare to improvise a dance to a tune you don't know, which will be performed in a way you have no way of predicting?

That's the challenge that Ririe-Woodbury Dance Company has taken on, for its upcoming evening of dance/vocal collaboration with jazz great Bobby McFerrin.The four-time Grammy Award winner for best male jazz vocalist (1985-88) will be making a return of sorts to Utah, where he worked and studied during the mid-'70s.

Don't expect a printed program listing dances one, two and three, when you sit down in the Capitol Theatre on Friday or Saturday night at 8. And don't expect to just sit there, either. You might become a part of the show, as a "choir" of audience members or a "backup group," because McFerrin thinks audiences should work a bit, not just relax and leave the creative process to the artists on stage.

The company's preparation has been typically Ririe-Woodburian, and boils down to trying to anticipate how you would react to an explosion; since for the past few years McFerrin has been affecting his audiences explosively.

Actually, his explosions are rather small-scale and amiable, more on the order of bubbling geysers, with little chirps, pops and squeaks from throat, tongue, lips and vocal cords punctuating his songs, which feature extreme leaps from bass to falsetto and body percussion --clapping, stamping, slapping his chest.

"I don't memorize my things, and nothing is ever really the same way twice," McFerrin told Laura Van Tuyl of the Christian Science Monitor. "Everything is improvisation...which is simply problem-solving."

He's one of a kind, and Ririe-Woodbury looks forward to working with him. Are you practicing? we asked Joan Woodbury. Yes, like crazy! was her emphatic reply.

"Our dancers are programmed so that some of the dances will be totally improvised, others will be totally set. We have to develop our skills in the areas we feel we might cover. We'll ask Bobby for some specific songs, for thematic material on which he or we or both of us simultaneously will be improvising. We hope that our program will feel spontaneous. There will be lots of short pieces, because songs are short.

"Bobby was in Salt Lake City as a student for a couple of years, and it 1977, I believe, he played for our dance classes," said Woodbury. "He was and is a wonderful keyboard artist. When he played for our improvisation class, he was just discovering that he had a voice, and experimenting a little. He got a job playing at the Hilton piano bar. He met his wife Debbie here, and they went on to New Orleans.

"Since then we have seen his career take fire, his name emerge in so many contexts. When we found he had begun working with Tandy Beal, even touring with her, we tried to arrange something, and just this year we were able to get together."

Until now, Beal has been the only dancer to work with McFerrin, in a collaboration that has been exciting and productive for both. "Since we got together three years ago, he and my company have produced the TV program Voice/Dance, which has shown on public television," said Tandy.

"You can't really pin down how we work, we keep changing so we stay really spontaneous. People are frightened by the term 'improvisation,' they think it means you don't know what you're doing. But improvisation has a long history in music and in dance, and presupposes inventiveness, technique and ability stored in your mental computer.

"Bobby is very joyful, and working with him brings joy to us as dancers and to an audience; he makes you glad to be alive. He's a wonderful artist and a wonderful human being," Tandy concluded.> Reached by telephone, McFerrin talked a little about his new album, "Simple Pleasures," the first in which he has layered sound tracks. Several of his own compositions include the title song, and "Don't Worry, Be Happy" --songs that come from his personal experiences. "I sing about how my day begins, I get up about 6, read, get the kids up, make breakfast, get my wife up. It's a happy time, it makes a good song."

Considering his family life of utmost importance, McFerrin often refuses attractive work offers if they keep him away from home for too long.

McFerrin's father, baritone Robert McFerrin, was the first black man to sing at the Metropolitan Opera. His mother heads the voice department at U. Cal in Fullerton. Yet they never tried to channel him toward their bent, though he did study all sorts of classical music-- besides piano, composition, flute, cello, and many other instruments. But always there was the drive to be "authentic," to improvise.

He thinks that's a healthy urge, which he teaches in occasional workshops on vocal improvisation. "People should stimulate their creativity," he said, "and that takes imagination, daring to try, living improvisationally, being open to possibilities, thinking for ourselves. Kids like music, and that's often the best avenue for them to open up their own creativity."

"The real task of any artist is to get inside people and change them-- enlarge their hearts," McFerrin told Van Tuyl. He has indeed tapped into the American imagination and heart, as dozens of recognitions attest.

Besides best male jazz singer, he recently collected another Grammy for 1988-- best children's record ("The Elephant's Child" with Jack Nicholson). And Downbeat has declared him best male vocalist for the fourth consecutive year, with more votes than any artist in any category.

This public adulation had its beginnings in private, in McFerrin's insistence on being quite unlike anyone else. "First was the vision, then the technique of working it out," he said. "I knew that if I started listening to others it would take me years to develop, so I shut myself off from other singers for a long, long time."

By 1979, when the McFerrins moved to San Francisco, Bobby was firmly committed to jazz. Since then he's appeared with the greats of the jazz world --with Phoebe Snow in his debut album of 1982, "Bobby McFerrin:" with Herbie Hancock, George Benson and Dizzy Gillespie. His life has crossed those of Jon Hendricks, Bill Cosby (theme music for '87-'88 among much else), Joni Mitchell, Wynton Marsalis, Grover Washington Jr. and Chico Freeman.

In 1983, McFerrin gave his first solo voice concert in Ashland, Ore. Insisting on going solo in a European recital tour, he survived initial skepticism that turned to enthusiastic approval, and went on to record "The Voice," a cappella in Germany in 1984. Ever since, he's in constant demand for solo concerts, in America and throughout Europe.

Just a few McFerrin projects of the past few years: appearing on Garrison Keillor's Prairie Home Companion; singing the male leads in an arrangement of Bach's Magnificat in Toronto; recordings with the Weather Report, Joe Zawinul, and the Manhattan Transfer; and performing in a cave as Merlin the Magician with 135 musicians for Austrian TV.

He's sung in Poland, Brazil, and Japan, and a week at the Theatre de la Ville in Paris. He's toured the country with comedian Robin Williams, and made a solo voice commercial for Levi's 501 Blues. his video recording, "Spontaneous Inventions" is available either in videocassette or laserdisc. Watch for him on Saturday Night Live on May 7.

The list goes on and on, at home and abroad, in every entertainment medium. With such a miscellany of activities, can he keep his life in focus?

"Yes, I do have a focus, on composing and recording," he replied. "I don't want to do too much performing these days, I see that there is just not time. I want most to make more and more recordings, using my own songs."

Tickets at $12, $15 and $25 are available at the Ririe-Woodbury box office in the Capitol Theater, Monday-Friday from 11 a.m. to 6 p.m., or at Smith'sTix. Following Friday night's concert, meet McFerrin at the sixth annual Backstage at the Capitol fund-raising party, with food provided by more than a dozen establishments. Tickets for Backstage are an additional $15, tax deductible, available in advance or at the door.