Spanish soprano Montserrat Caballe is one of the great sopranos of the 20th Century, known for her exquisite vocalism, the wide range of roles she undertakes and the devotion she inspires in her fans. When she makes her sole American appearance of the summer at Ravinia Saturday, Chicago audiences will have their first opportunity in more than 10 years to hear her live, in a concert of selections from opera and zarzuela.

In her long career–she made her professional debut in 1956–Caballe has given more than 3,800 performances in 88 roles on five continents, with a repertoire that ranges from operetta to Wagner. Although she is best known for her performances of such florid roles as the leads in Bellini’s “Norma” and Verdi’s “La Traviata,” she avows a particular affection for the operas of Mozart and Richard Strauss.

“I did hundreds of performances of Mozart early in my career,” she says by phone from her home in Spain. “It is a good basis for the sound, a good basis for producing different kinds of vocal expression.” As for specific roles, “I always will cherish in my heart Strauss’ Marschallin and Salome.”

Caballe has adapted her remarkably flexible vocal instrument to sing in many different compositional styles. “There is only one voice, the one you are born with. When you are a singer, you must do all you can do in your younger years to learn a good technique, and you use that technique in everything you sing. Then you learn the different styles, so that you can approach them properly.

“Because of this, I have been able to sing so many different things–`La Traviata,’ `Semiramide,’ `Tristan und Isolde,’ `Der Rosenkavalier.’ These are very different operas, but they are all very romantic! It is wonderful to have the possibility to enter these different worlds, and I feel so very fortunate. I have a very wonderful and exciting life.”

Born in Barcelona in 1933, Caballe–she was born Maria de Montserrat Viviana Concepcion Caballe i Folch–was a refugee for a brief time in 1939, during the Spanish Civil War. But the next year, after the family returned to their bomb-damaged home, she was taken to her first opera, “Madama Butterfly.” She set about to learn Cio-Cio San’s great aria, “Un bel di,” and sang it for her parents as her Christmas present to them. Soon after that, she began her formal musical studies.

Money was tight, and her studies were often interrupted. As a teenager, the young singer spent eight months toiling in a handkerchief factory, and then came to the attention of a wealthy family, the Bertrands, who agreed to sponsor her studies. She made her professional debut in Basel, Switzerland, in 1956, a last-minute replacement as Mimi in “La Boheme.” Soon she was singing all over Europe, and then all over the world, creating a sensation wherever she went. Along the line she found time to marry a colleague, tenor Bernabe Marti, and have two children, a son and a daughter.

Her training was old-fashioned, with a regimen of many months of vocal exercises before her teacher allowed her to begin work on arias; it’s a discipline that repaid her with her characteristic high pianissimo and a long career in many different roles. Her ample physique, too, harks back to a day when appearance was a minor concern in casting operas. But her pure, expressive voice has carried her performances; when you can produce a ravishing sound consistently, other considerations fade, and that ravishing sound–still present, according to reviews of last fall’s Carnegie Hall recital–made her career.

“I have so many wonderful memories, so many moments that I treasure very much–singing `Semiramide’ with Marilyn Horne, my first `Norma’ at La Scala, singing `Il Trovatore’ at the Metropolitan Opera with Placido Domingo, my first `Turandot’ in San Francisco with Luciano Pavarotti,” she recalls. “They were all special nights–all very different, but all very emotional.”

But along with international fame and acclaim began to come a reputation for canceling. Although she has missed a relatively small proportion of the performances she was supposed to do–about 200 in all, over almost 40 years–many of them were high-profile engagements at the peak of her career, and the cancellations clouded her name with some impresarios and the ticket-buying public. In fact, many of those cancellations seem to have been brought on by her desire to please the public by singing a great deal in many different venues. To a certain extent, she made herself ill with overwork and travel.

“I cancel when I am sick,” she says, simply. “I have had seven major surgeries in my life. I have had tumors. I have had two children with caesareans; you don’t just get up and sing the day after one of those. I was in an accident in 1969 in New York that required surgery and took four months for me to recover. I don’t cancel because of temperament.”

Caballe has not sung at Lyric Opera of Chicago since 1973, when she left in mid-production and the late Carol Fox, the founder and then-general manager of the company, brought suit against the singer for breach of contract. (Caballe won.)

“I had phlebitis, which is really very painful, and my son was in a coma from salmonella. Miss Fox said I could go in case of a real emergency; I told her, `When he’s dead, I won’t need to go. He needs me now.’ The things that make you human come before being a singer.” Caballe says she has had discussions with current Lyric general director Ardis Krainik about returning to the theater, “but we have not been able to make the dates work for me to come.”

Krainik confirms that Caballe’s continued absence from Lyric has been a matter of conflicting dates and schedules. “If we were not in the midst of our renovation, Montserrat Caballe would definitely be the first choice of a recitalist at Lyric Opera,” she says.

When it’s noted that some admirers call her “the last prima donna,” Caballe gives a little shriek of dismay. “That gives me a horrible feeling. I know they mean well, but it sounds very strange to me. What does it mean? Of course there are other prima donnas. So many of my colleagues, younger ones, are wonderful.”

A suggestion that “the last prima donna” title is a reference to her membership in an occasionally temperamental but vocally outstanding roster from an earlier era that includes Maria Callas, Joan Sutherland and Renata Tebaldi is ruthlessly cut short: “When I began, Maria Callas was already retired. Joan Sutherland began much, much earlier than I. Tebaldi, too–I saw her as a student in Barcelona. No, I do not like this name.”

She also dismisses questions about retirement. She intends to go on for as long as she can. After the discovery of a tumor beneath her brain in 1985 (she opted to skip surgery, but had laser treatment for it; she says she assumes that it’s benign), Caballe cut back her schedule. “I was told to do less opera and more concerts. With opera, you must be there for months, rehearsing and performing, but a concert takes very little time and is much easier. I have realized that I don’t have to exhaust myself. Now I do two operas a year, some recitals with piano, and some concerts with orchestra.”

She’s still working on new roles, though: She plans to do her first-ever performances of Strauss’ “Elektra” in Athens, Greece, in 1998, in a production that will be videotaped as well as performed live. She’s to do “Medea” in the same venue in 1997. “I think it is very exciting to do these operas in the places where the stories happened,” she says.

She often sings in benefit concerts for children’s hospitals. And, as a result of her association with the late rock star Freddy Mercury of Queen–with whom she had a crossover hit in the song “Barcelona”–Caballe has become involved in AIDS awareness.

Her program at Ravinia is scheduled to include Desdemona’s “Willow Song” and “Ave Maria” from Verdi’s “Otello,” along with a pair of French selections, “Il est doux, il est bon,” from Massenet’s “Herodiade,” and “O ma lyre immortelle,” from “Sapho,” by Charles Gounod.

“I have always loved the French operas,” she says, “but my career developed in a different way.”

The second half of the concert is to be devoted to arias from zarzuela, the Spanish form of music theater.

“Some of the songs are romantic, some are giocoso , but they are all very Spanish.”

One final question: How is her health now? Caballe giggles, a surprisingly girlish sound.

“I feel fine.”