The final act of Rimsky-Korsakov's "The Tsar's Bride" is about to begin and Galina Vishnevskaya, the celebrated Russian soprano, is lost in the bowels of the Monte Carlo opera house.

"Where we must go, where we must go," she shouts frantically in the pidgin English she has acquired after a decade of living in the West with her husband, cellist and National Symphony music director Mstislav Rostropovich.

The underground maze of poorly lit passages in which we are trapped contrasts with the brilliance of the scene upstairs: a magnificent stage set conjuring up Russia under Ivan the Terrible, a gala audience dripping with jewelry and fur coats, the sumptuous red and gold decoration of the 100-year-old theater.

Vishnevskaya -- whose eventful lifetime has included such episodes as living through the German siege of Leningrad, receiving the unwelcome attentions of a lovesick Soviet president and sheltering the Russian writer Aleksandr Solzhenitsyn -- is in the process of creating a new role for herself. At the age of 58, she has turned from singing to directing. Her staging of "The Tsar's Bride," an opera performed frequently in Russia but scarcely known in Europe and America, will open at the Kennedy Center in November.

A Russian boyar, dressed in high boots and flowing cloak, appears before Vishnevskaya. In the second act, he was swaggering about on stage, lording it over the masses. Right now, he is the picture of obsequiousness as he leads the opera star back through the elaborate sets to her rightful place on the other side of the curtain.

There is something about Vishnevskaya, who held the rank of "People's artist of the Soviet Union" before she and Rostropovich were unceremonially stripped of their Soviet citizenship in 1978, that encourages people to fawn. Her regal manner reflects her status as one of the grande dames of world opera. It contrasts with the contagious extroversion of her husband, who is apt to kiss and hug anybody who crosses his path.

The first coproduction between the Washington and Monte Carlo operas, "The Tsar's Bride" also marks a new form of collaboration for one of music's most distinguished husband-and-wife teams. While Vishnevskaya is responsible for the staging, Rostropovich is in charge of musical direction. Their aim was to re-create a little slice of the old Russia in the West.

bat10 In Monte Carlo for the opening night, Martin Feinstein, the director of the Washington Opera, explained that the idea of putting on the Rimsky-Korsakov opera originated in a conversation he had with Rostropovich four years ago. Symphony director Rostropovich was eager to tackle an opera for a change. But he also wanted to broaden the U.S. opera repertory.

"We wanted to get away from the old Russian war horses like Boris Godounov and Eugen Onegin," said Feinstein, noting that the six Russian-language performances of "The Tsar's Bride" in Washington will mark the opera's first known staging in the United States.

The use of surtitles at the Kennedy Center will enable Washington opera-goers to follow the complicated plot of love and intrigue at Ivan the Terrible's court -- the complexities of which were lost on the first-night audience in Monte Carlo earlier this month. The transfer to Washington will also provide more space for a production that seems somewhat cramped and unimaginative on the small Monte Carlo stage.

Monte Carlo may not rank with great European opera houses like La Scala and Covent Garden -- but it has sentimental value for Russians. Built in the incredibly short period of six months in 1878 as an evening diversion for gamblers at the casino next door, it was the home of Diaghilev's famed "Ballet Russe." It was here too that the great Russian opera singer Chaliapin sang "Don Quixote."

Monaco, a tiny principality on the French Riviera that includes the town of Monte Carlo, also provided Rostropovich and Vishnevskaya with a temporary place of refuge after a long struggle with the Soviet cultural authorities. The two were lured to Monte Carlo as a result of a longstanding friendship with the late Princess Grace, and it was here that they performed their first recital together after leaving the Soviet Union for good in 1974.

"We Russians like it here. It's hard to explain why, we just do," said Rostropovich, his wife nodding beside him.

For the Washington Opera, the main attraction of staging a coproduction with a foreign company is the money saved on sets and costumes. The U.S. budget for six performances of "The Tsar's Bride," according to Feinstein, is $400,000.

bat10 Lavish spending on culture fits in well with Monaco's image as a playground for the super-rich. With a population of just 24,000, it features an extraordinary array of cultural activities from its own ballet company, orchestra and theater to an oceanographic museum and circus (described by aficionados as possibly "the only black-tie circus in the world").

"It's very old-fashioned, almost Mozartian. This is one of the few places left where you can work for a prince. We are court musicians," said Ronald Patterson, the orchestra's California-born musical director.

For Monaco devotees, the principality is a haven of security (there are more police per head than in any other country in Europe), where it is possible to walk around late at night wearing one's jewelry with no danger of being attacked. The cultural delights Monte Carlo has to offer are matched only by the ostentatious display of wealth. Among other things, the town boasts one of the most profitable Rolls-Royce dealerships in Europe.

For outsiders, Monaco can be strangely claustrophobic, hemmed in both by the mountains, which rise sharply above the port, and by the narrowness of the country's political and social life. Everything -- from parties to street signs to politics -- seems to revolve around the royal family and the sovereign, His Serene Highness Prince Rainier III. Boredom is a common complaint on the Monte Carlo social circuit.

The flavor of the place was captured in a comment overheard at Rampoldi's, a fashionable and expensive Italian restaurant just around the corner from the opera house. "I wish you love and good health in 1985," said the maitre d', casting an appreciative eye over the mink coat of one of his regular woman clients. "I am not going to say wealth as well, since you have obviously plenty of that already."

The money Monaco lavishes on culture can prove formidable competition for impresarios elsewhere. Feinstein remembers one particularly tough bargaining session with a singer who sought to get a better contract by telling him how much she was earning in Monte Carlo.

Recalling that he had seen singers gambling away their earnings in Monaco on the craps tables and one-armed bandits, the director of the Washington opera replied: "If there were a casino next door to the Kennedy Center, I could afford to pay you that kind of money too."