In 1977, three years after master cellist Mstislav Rostropovich left the Soviet Union, he was on the cover of Time, hailed as the possible savior of the National Symphony Orchestra.

Now after more than a decade in the West, the talented, ebullient Rostropovich -- superstar in exile -- has been rewarded by more than applause.

He is rich.

Last year -- the 1984-85 season -- the maestro received $606,250 for his work as the NSO's music director and conductor, according to figures released by the orchestra's new executive director, Stephen Klein. During the past three years, Rostropovich received nearly $1.5 million from the orchestra, including $372,623 for the 1983-84 season and $488,000 for 1982-83.

In addition to his NSO pay, Rostropovich is said by an informed observer to receive $20,000 to $35,000 for a cello solo. According to an NSO spokeswoman, he performs about 70 such solos a year outside his NSO activities. A simple calculation suggests that he receives $1.4 million to $2.4 million a year from this solo work.

He also receives income from other musical activities, such as recording.

In a recent telephone interview from Paris, where he owns a luxury apartment, Rostropovich chatted amiably for 45 minutes about his financial and other personal arrangements. He said he could earn as much playing the cello in a month as he earns as a conductor in a year.

"I am not the highest paid conductor," he said. "And I am not the highest paid soloist in the world, though I may be one of them."

He said he did not know his total annual income from all sources.

At the request of The Washington Post, Klein provided, with Rostropovich's approval, detailed breakdowns of the maestro's NSO earnings for the past three fiscal years -- a depth of disclosure unusual in the financially sensitive world of the big orchestras.

Last year -- the 1984-85 season -- Rostropovich's $606,250 NSO income consisted of $145,000 for administrative and other duties as orchestra director; $116,000 for eight weeks of conducting during the regular subscription season (or $14,500 per week); $29,000 for leading the orchestra's two-week midwestern tour at the standard weekly rate; $263,300 (or $52,660 per week) for its five-week European tour; $15,000 for concerts at Wolf Trap; $20,000 for a cello solo; $7,500 for a concert carried by Maryland Public Television; $450 from radio revenues; and $10,000 in a pension plan.

The two main components of Rostropovich's NSO pay for the three years disclosed were the set amount for his duties as music director, and a second portion for conducting sw,-2 sk,2 ld,10 seven to nine weeks of the regular subscription concerts at the $14,500 per week rate (or $3,625 to $4,833 per concert depending on whether there were three or four concerts a week) as set by Rostropovich's written contract.

The maestro's other compensation in any of the three years varied depending on what tours and other activities Rostropovich participated in with the orchestra. Klein described much of this other compensation as "conduit moneys" paid to Rostropovich through the NSO, mainly by sponsors who arrange with the symphony and its director to give concerts on tours. These "conduit moneys" were high last year -- $299,800 (including $263,300 for the European tour) of Rostropovich's total $606,250 NSO-related income.

"We believe this is a firm indication of the rising esteem for the artistic combination of Maestro Rostropovich and the National Symphony," wrote Klein in a footnote to the numbers.

During the 1982-83 and the 1983-84 seasons, the additional payments to Rostropovich included: $5,000 for conducting a July 4 concert on the Capitol grounds, for which Congress appropriated special funding; an additional $5,000 from the televising of that concert; $165,000 (or $47,142 per week) for leading the NSO's 3 1/2-week tour of the Far East; an additional $5,000 from the televising of that tour; $81,600 (or $40,800 per week) for leading the NSO's two-week tour of South America; and $7,500 each for a special concert for the International Monetary Fund and a "run-out" to the Garden State Arts Center in New Jersey.

The NSO is more than $4 million in debt and lost $395,000 during fiscal 1985.

Klein said Rostropovich is worth his pay, that the maestro brings "electricity" and "visceral excitement" to the orchestra. The Rostropovich name means, according to Klein, that "We can get a whopping fee out of different cities" on tour.

"He's made this into one of the world's great orchestras," said former NSO president Leonard Silverstein. " . . . I felt he was our best investment."

Rostropovich's NSO compensation places him "above the average, but not at the summit" for directors of major American orchestras, says one informed observer. The Boston Symphony Orchestra's Seiji Ozawa received $418,750 for the 1983-84 season and $364,750 the year before, according to The Boston Globe. For generations Boston's has been considered one of the "Big Five" orchestras with the Cleveland Orchestra, New York Philharmonic, Chicago Symphony and Philadelphia Orchestra. While even Rostropovich's predecessor Antal Dorati agrees that the NSO has improved under Rostropovich, it is not widely considered to be in that league.

Comparing music directors' compensation is difficult. Some have big expense accounts that others don't. In a 1984 article based on public Internal Revenue Service documents, The Milwaukee Journal listed Sir Georg Solti's 1983 salary with the Chicago Symphony as $333,583, and the 1982 salary of Carlo Maria Giulini, then music director of the Los Angeles Philharmonic, as $601,270. Given Solti's preeminence in the music world, the difference seemed unlikely, perhaps accounted for by expense or other undisclosed reimbursements. Klein said Rostropovich does not have a large expense account.

"He's not reimbursed for his housing in Washington, which some music directors get," Klein said. Rostropovich owns a condominium near near the Kennedy Center. "He's not reimbursed for his travel to and from Washington . . . He's not given a living allowance."

Rostropovich "rarely" asks to be reimbursed for business meals and pays for his own phone calls except for those he makes directly to the NSO offices, according to Klein. "I'm sure he's calling Europe," said Klein, "and I'm sure he's calling all over the joint, but I'm not getting charged for it."

To earn his pay as NSO conductor, Rostropovich is with the orchestra in Washington or on tour about 15 weeks a year. In addition, as music director, he makes himself available for telephone consultation year-round and "for planning, fund-raising efforts, public relations, administrative activities, press conferences, etc.," Klein said.

"I definitely lose money to work as a conductor," Rostropovich said. "I'll give you an example. When I have guest soloists with the National Symphony, they have a maximum of two rehearsals. But for the conductor, the NSO takes four complete rehearsals a week, with enormous time, plus four concerts."

In the season now drawing to its close, Rostropovich is being compensated at a new weekly rate for 10 weeks of conducting under a newly signed three-year contract, but he and Klein both refused to disclose the rate or other details of this contract.

"Let me put it this way," said Rostropovich. "We have made a contract on terms that do not insult one in my position."

While Rostropovich -- often described as passionate, dynamic and brilliant -- has reveled personally and artistically in the freedom of the West, he now finds himself somewhat restricted by the "day count" provision of the U.S. Tax Reform Act of 1984.

Under it, Rostropovich, who said he still considers himself a Soviet citizen but who travels on a Swiss passport (an NSO spokeswoman said he also has "travel papers" from Monaco), must not be in the United States more than a certain number of days a year -- roughly a third of each year -- calculated according to a complex formula in the tax code, or he risks having his worldwide earnings taxed by Uncle Sam.

As a result, Rostropovich sometimes jets to Canada for the weekend between conducting engagements in Washington. Under the tax code, if any portion of a day is spent in the United States, it is counted as a full day.

"It is a real problem for me," Rostropovich said. "Because of it, some weekends I come out from the U.S." His day count is kept by his manager at Columbia Artists in New York, Ronald A. Wilford.

"We all cooperate a lot on that," said Klein of the day count.

The NSO pays Rostropovich's earnings into a corporation registered in Delaware, Pooks Concerts Inc., set up in 1977 with Rostropovich as president; his wife, the opera star Galina Vishnevskaya, a vice president; and Wilford a vice president, secretary and treasurer.

The corporation, which provides tax advantages, was named after Pooks, Rostropovich's beloved miniature dachshund, which has since died of a heart attack.

Rostropovich said Pooks Concerts Inc. makes it possible "to have centralized all my work in America, all my activities." Orchestra officials said Rostropovich pays taxes to various countries depending on how much money he earns in each and what their tax requirements are.

The pace of Rostropovich's life abroad is frenetic. In January he and Vishnevskaya staged and directed Rimsky-Korsakov's "The Tsar's Bride" at the Monte Carlo Opera house. In the weeks that followed, as reporters and NSO officials sought to contact him for this story, he was in Switzerland, then London, then on tour in Italy, then Paris.

Rostropovich said he wants to give "an honest, complete picture" of his financial situation. He said he was upset by a critical article in the January issue of The Washingtonian Magazine that listed his $488,000 NSO earnings for the 1982-83 season; the article added: " . . . and this for 15 weeks of work. Is he worth it?"

"I think the article was a slap in the face," Rostropovich said. " . . . There are all these problems for the orchestra that just do not exist for the solo cellist. I am constantly monitoring new performers. Every time I go to Europe, I am looking for new guest conductors who can replace the ones who are falling off. One is not paid for that time."

Orchestra officials say Rostropovich earns his pay; Edward Birdwell, director of the music program at the National Endowment for the Arts, says that, concerning orchestra directors generally, "It's become more and more controversial about these six-figure salaries for a few weeks a year."

Birdwell says that as orchestras struggle to raise money and make ends meet, "More and more people are saying, 'Wait a minute, what the hell is going on here?' "

While Rostropovich took a sabbatical leave during 1984, the maestro was still paid both his music director's and conductor's salaries. Klein said Rostropovich continued to do his music director job, mostly by telephone; and he conducted seven weeks of regular subscription concerts for the 1983-84 season before the sabbatical began in January 1984.

"Even though he was on sabbatical, he still flew in here for meetings and fund raising," said Klein. Later, "He interrupted his sabbatical. We got a sudden invitation to do the tour in South America, so he said, 'Yes, I'll come back and do it.' "

During that 1983-84 season the orchestra's principal guest conductor, Rafael Fru hbeck de Burgos, received $112,350 in conducting fees from the NSO, according to an NSO tax return for tax-exempt organizations routinely made public by the Internal Revenue Service.

That tax return and the one for the previous year showed that the orchestra's direct public support in the form of contributions, gifts and grants decreased from $6.1 to $4.5 million, and government grants dropped from $1.3 million to $754,900 from one year to the next.

In November 1984, the financially pressed NSO launched a $20 million endowment drive. An orchestra spokeswoman said that so far the endowment has reached $10.5 million with pledges for another $6 million.

As music director, Rostropovich auditions and chooses new players, chooses the programs, and determines guest artists and conductors. During Rostropovich's tenure, according to orchestra officials, 38 new orchestra members have been chosen and the NSO has been expanded in size.

Both Klein and Silverstein praised Rostropovich's intense fund-raising efforts on behalf of the NSO. In 1982, officials of Amway, a national household products firm, underwrote a month-long European tour for the symphony because they wanted to link the Rostropovich name to their new European sales campaign. That same year, industrialist Armand Hammer made a $250,000 gift to the orchestra, then doubled it in a burst of enthusiasm after Rostropovich embraced him publicly on stage.

During the past three years, Rostropovich in several instances donated his services both as conductor and cello soloist. During the 1982-83 season, he conducted concerts at Wolf Trap for free and also, that season and the following one, performed as a cellist with the orchestra for a week at no charge.

"I donated those concerts at Wolf Trap because they were benefits for building the new Filene Center," Rostropovich said. " . . . Donations will vary from time to time. For instance when Leonard Bernstein conducted his 'Meditations' from 'Mass' . . . you know he is a very expensive conductor, so I contributed by playing of the solo cello . . . I have done this maybe five or six times."

Rostropovich is a frequent and voluble personality on the Washington party circuit, where he can often be seen drumming up financial support for the NSO.

Said the maestro: "I have a real feeling for Washington, because for nine years it has been very much a part of my life."