When you contemplate attending an opera, or any stage work for that matter, you're usually interested in two questions: what is it, and who's in it? The better you like the answers, the more likely you are to go.

Utah Opera audiences seem to have had a high satisfaction quotient with answers to both questions lately, since houses have been consistently sold out.And one sees little to suggest that things will be different with the season-ending double bill - the comic "Gianni Schicchi" by Puccini and Leoncavallo's verismo masterpiece, "I Pagliacci," at the Capitol Theatre on May 12, 14, 16 and 18.

Both are tuneful, accessible operas, with basic, engrossing plots. And both will be sung, in Italian with English Supertitles, by some of the country's outstanding young singers and experienced pros.

As Gianni Schicchi, a clever lawyer who out-finesses a pack of avaricious heirs, Giorgio Tozzi appears for the third time in Utah, for the many-hundredth time on the operatic stage. He was a star of the Metropolitan Opera for 20 years, and of other international companies including La Scala, Rome, Bavarian State and San Francisco Operas.

"I Pagliacci" (The Clowns) deals in two tautly constructed acts with a tragedy of vengeance among a troupe of traveling players, led by the aging Canio, who sees his beautiful wife Nedda drawn to a younger man.

"Pag," as it's often called, has an all-imported cast, led by Augusto Paglialunga as Canio, to whose lot falls the aria known to all as exemplar of a whole genre of passionate singing - "Vesti la giubba."

Gus sings with U.O. for a third time. He now teaches at the University of Washington in Seattle, after a distinguished career in Germany and Austria, including Freiburg Opera. He's sung at New York City Opera, and often performs with such regional operas as Seattle, Cincinnati, Arizona and Phoenix.

For Nedda, Utah Opera brings in Susan Marie Pierson, a winner of the second Luciano Pavarotti International Voice Competition. She sang opposite Pavarotti in "The Masked Ball" at La Scala, and has appeared with opera companies of Cincinnati, Pittsburgh, San Diego, Wolf Trap and Arizona. Baritone Stephen Lussman, another Pavarotti winner, sings for the third time in Utah as Silvio.

Robert McFarland's recent string of successes excites local interest in his appearance as the deformed Tonio. A leading baritone with New York City Opera since 1980, McFarland has also sung with Houston, Philadelphia, Miami, Cincinnati, Chautauqua, Toronto's Canadian, and Minnesota Operas. You may have heard his Amonasro in Houston Opera's telecast of "Aida" from the new Wortham Arts Center.

Well remembered as a graceful Almaviva in the 1987 "Barber of Seville," tenor Abram Morales does double duty - as the young lover Rinuccio in "Schicchi," and Harlequin in "Pagliacci." Morales' credits include New York City Opera, Canadian Opera, Seattle, San Francisco, Miami, Baltimore, Chicago, Houston, and many other houses.

But artists such as these look good at Utah Opera partly because of the firm infrastructure that supports them - strong organization and coaching staff, professional staging and stage management, costuming and lighting, and not least, a big collection of local singers capable of singing supporting roles with professional expertise.

Filling out a treasure trove of small comedy parts in "Gianni Schicchi," Utah singers Diane Beesley, William Goeglein, Kathryn Feigal, Dave Arnold, Susan Willey, Michael Wadsworth, Don Becker, Andrew McCarthy and Columb Robinson represent the sort of solid support that has developed here over the years.

So meet a few of Utah Opera's supporting singers, some of whom have been part of Utah Opera since its initial 1978 season. Tied to Utah by home, family, jobs and/or preference, all have given extensive service to the company's main stage productions, and all have worked in the opera's school programs, building the audience of the future.

Tenor Dave Arnold rivals Bill Goeglein for the title of "Mr. Utah Opera." He's been in every production (more than 30) at U.O., except the first "La Boheme," and he's a stage director/conductor's dream: a singer who invests a small part with personality, character and distinctive singing, and he doesn't mind contributing in the chorus if nothing bigger presents itself.

Arnold was born and reared in Los Angeles, where his father worked as a scenic artist in Hollywood for 50 years. He studied wind instruments, "but my mother pushed opera, and I escorted her to the theater from the time I was a little kid," he said. "All that opera must have been stored up in me just waiting to get out."

A budding career in professional baseball was shut down by a shoulder injury, and Arnold joined the service, eventually being stationed at Mountain Home Air Base in Idaho. A friend brought him in contact with Weber State College in Ogden, where he ended up on full, dual scholarship in music, both instrumental and vocal. "It took me a long time to graduate, what with the service and an LDS mission," he said.

Arnold taught band and orchestra in Weber and Davis school districts, but a little newspaper notice of auditions for U.O.'s "Tosca" changed his life. General director Glade Peterson liked him and put him in the chorus, promising more later. Beginning with Cassio in "Otello," Arnold has done with flair a long line of such small but telling roles as Remendado, Goro, Monastatos and Spoletta. Needing a less structured career than teaching to support his opera habit, Arnold now restores antique cars and helps his wife with Peggy's Doll Shop in Clearfield, purveyors of porcelain dolls. He'd like to extend his base into regional opera, has sung with Boise Opera, and auditioned with Nevada and Las Vegas Operas.

Bass-baritone William Goeglein has nearly made a life of Utah Opera during the past 10 years, singing a whopping 23 roles with the company, many of them sizable ones like Raimondo in "Lucia," Monterone in "Rigoletto," Colline in "Boheme" and the Speaker in "Magic Flute." Goeglein was born and reared in Holladay, and studied at the Academy of Vocal Arts in Philadelphia under Nicola Moscona. Deciding not to go for a professional career, he returned to Utah in time for Utah Opera's flowering. Among favorite roles, he cited Dr. Bartolo in the 1982 "Barber," and especially Ashby in "The Girl of the Golden West," which remains his favorite among operas he's sung.

Geoglein has also trimmed his workaday sails to suit the operatic gale, giving up a job as foreman for a building contractor to open his own painting business, in favor of flexible hours. He's also moving out - recently sang a Verdi Requiem, Tchaikovsky's "Joan of Arc" with Delora Zajac in Reno, has sung with Fargo-Moorehead Opera, a "Messiah" in Billings.

Sometimes Geoglein wonders if he should have gone to New York; but in general, he feels that his musical life here has been "a fair shake. I've made many friends - lifelong, close friends - at Utah Opera."

Kathryn Edwards Feigal first sang with Utah Opera in 1979, as Kate Pinkerton in "Butterfly." Since then her half-dozen roles have included Berta in "Barber of Seville" and Lola in "Cavalleria Rusticana."

Born Kathryn Schoenhals in Salt Lake City, she can't remember a time when she wasn't in music. She plays violin and guitar but didn't begin singing until she took student summer employment at the Grand Canyon, with nightly shows.

Setting aside performance for four children, she recently finished her music degree at the University of Utah. "Now I'm eminently equipped to write LDS roadshows," she laughed, as she prepares to charge through an MFA in playwriting, another big interest. "Music and writing are my best therapy," she said. "I love to pick up my violin and play - though when I was practicing the other day my son stuck his head through the door and said, stick to singing, Mom!"

The wife of Dr. David Feigal, Kathy said she's exactly where she wants to be, both personally and professionally, and she thinks there's no place like Utah Opera. "It's my favorite place to sing, we're like family here."

Diane Beesley burst full-blown upon U.O. as Mistress Page in "The Merry Wives of Windsor" (1982). But like most "instant" successes, Beesley had a string of musical conquests behind her, including many here before Utah Opera came along.

She's married to Gary Beesley, of the musical Beesleys. "My mother-in-law is Evangeline Beesley, now 94, who used to sing mezzo soprano with soprano Emma Lucy Gates," Beesley said. "All my children love opera. My son sings around the house in a booming bass, and two of our kids are in `Pagliacci."'

The last of five children (now 7 to 17) being reasonably well launched, Beesley first took on the maid in "Lucia;" and with her rich, incisive mezzo and acting ability, she's building a loyal following. (Remember her as the ancient Berta afflicted with sneezies in last year's "Barber of Seville"?)

Reared in Los Angeles, she "walked in off the street" to become a competition finalist; sang opera and musical comedy at Brigham Young University, and won the Utah State Fair and Salute to Youth competitions. She studied in Wiesbaden, Germany, also in New York, then returned to Utah for the heyday of opera at the U. of U. in the mid-'60s. She's also sung and recorded with the Utah Symphony. Beesley is well satisfied with her range (which incidentally includes a singable high C). "Everyone is competing for the soprano parts, but a good mezzo is hard to find," she said.

Logan-born Susan (Deauvono) Willey was a youngster of 20 when she sang Musetta in Utah Opera's first production of "La Boheme." The pretty brunette, who sang Papagena last fall, looks scarcely older now.

"Less than a month after I had my baby, I was singing Rosina in `Barber of Seville,' she recalled. She's sung Ann Page, Adele in "Die Fledermaus," and second lead in "The Merry Widow" with Roberta Peters. She's understudied a great many parts _ Queen of the Night, Norina, Musetta, Adina, Rosina _ the -inas and -ettas, as they're known among soubrette sopranos. "I had to learn Rosina in Italian in two weeks, and prepare to sing it in mezzo range to understudy Marta Senn," she recalled.

She too has her eye on moving along and accumulating some credits, auditioning with more regional companies.

James Meena conducts the Utah Symphony, the chorus is prepared by music director Gordon Jephtas, costumes are by Susan Memmott Allred and lighting by M. Kay Barrell. Sets come from Portland Opera.

Tickets ranging from $10 to $30 are on sale at the Utah Opera box office in the Capitol Theatre, weekdays from 11 a.m. to 5:30 p.m., or telephone 533-6494 for charge card sales.