"I was 4 years old when Jean Sibelius died in 1957," conductor Osmo Vanska reflected recently. "Neither of my parents were professional musicians, and yet my mother was weeping when she told me, and I remember it as if it were yesterday. The whole country went into mourning; thousands of people attended the funeral. I can't begin to describe what Sibelius meant -- what Sibelius continues to mean -- to Finland. He was not only our greatest composer but, in many ways, our greatest figure of any kind -- a towering, lonely giant."

How Sibelius would have marveled at what has become of his native land, for he certainly wouldn't be "lonely" today. Finland, a small, sparsely populated country of 5 million citizens, boasts a musical life of astonishing richness and diversity. In addition to Vanska -- who will lead the National Symphony Orchestra this week in a program of Mussorgsky, Shostakovich and Rachmaninoff -- the list of leading conductors from Finland includes Esa-Pekka Salonen, the music director of the Los Angeles Philharmonic; Jukka-Pekka Saraste, until recently the music director of the Toronto Symphony and now rumored for a number of different appointments; and Mikko Franck, a brilliant unaffiliated conductor in his early twenties who has already made spectacular first appearances with the principal orchestras of Berlin, Chicago and Washington. Indeed, as the critic Andrew Clements observed recently in the (London) Guardian, "There must be more conductors of international class per capita in Finland than anywhere else in the world."

Washington has come to know Vanska, 49, very well over the past couple of years. He made a much-admired debut with the NSO in 2000 and returned last summer to conduct what was billed as a "Festival of Favorites." That meant he had to take the orchestra through three programs of considerable difficulty in as many nights. It didn't work -- it couldn't have worked, and Vanska was clearly frustrated: No orchestra could prepare a trio of such challenging programs in so little time. But the best moments -- especially a rendition of the Sibelius Symphony No. 2 -- were little short of incandescent.

I heard the rehearsal of the Sibelius, which was spacious and meticulously detailed. Vanska understands that the listener must always be aware of the backdrop of silence that pervades Sibelius's music, even when all the instruments are roaring gloriously at full throttle. His gestures to the orchestra were authoritative and unmistakable -- to indicate a diminuendo, he crouched way down, almost kneeling, while climaxes were led with an inflated chest and a wide, proud, waving of the arms. His comments to the musicians were polite, probing and specific, and he never wasted time. When the rehearsal came to an end, the players stamped their feet in approval -- the ultimate insider accolade. He has already won the orchestra's respect. And this time around, he will have a full set of rehearsals.

Vanska is much in demand these days. He has served as the music director of the Lahti Symphony Orchestra in Finland since 1988, making more than 40 recordings, including some 15 discs in a complete Sibelius edition for the Bis label. In the past few years, he has conducted several of the finest American ensembles (Cleveland, Chicago, St. Louis, San Francisco and Philadelphia, among others), and next fall he is to become the music director of the Minnesota Orchestra. He will conduct the NSO in three subscription series this year, returning in April with programs of works by Sibelius, Brahms, Ravel, Debussy and others.

He greets a visitor with the blend of cordial interest and soft-spoken reserve that anybody who has spent time in Helsinki will recall as typically Finnish.

"We have been an independent country only since 1917, and we had to fight hard for it," Vanska said. "Even after independence, we were invaded by Russia and had to fight all over again. And so we take things very seriously in Finland -- whether politics or music."

Vanska's family came from Karelia, a much-disputed peninsula only 200 miles from St. Petersburg. "When Karelia was annexed by the Soviet Union during World War II, my parents fled," he recalled. "As I get older, I feel more and more Karelian. It has such rich music, food, folklore, all sorts of art."

He began violin studies when he was 8. "I remember resenting it enormously because my father would come pick me up in the middle of soccer practice to take me to music school. But by the time I was 12 I had taken up the clarinet, and from then on, I never wanted to be anything other than a musician." By age 18, he had quit school and become the principal clarinetist in the Turku Philharmonic. "I was very proud, because in those days that was the best Finnish orchestra outside of Helsinki."

While in Turku, Vanska supplemented his duties by leading a choir and working as an arranger. In 1975, when he was 22, he conducted one piece -- Mozart's Symphony No. 36 ("Linz") -- as part of a Turku Philharmonic performance in an old castle. "But it wasn't until 1977 that I decided I really wanted to conduct full time. I enrolled in the Sibelius Academy as one of four conducting students of Jorma Panula. One of my classmates has since died; the other two were Esa-Pekka [Salonen] and Jukka-Pekka [Saraste].

"As you can see, it is a pretty small world. All Finnish musicians know each other and we cheer each other on. There's really no competition because there is so much work to go around. Oh yes, I used to wonder whether I could have a great American orchestra like Esa-Pekka" -- Salonen was named music director in Los Angeles when he was only 31 -- "but real jealousy? No. That's not the way I am. That's not the way we are."

Vanska won first prize in the 1982 Besancon International Young Conductors' Competition; he came to Lahti three years later as the principal guest conductor and became its music director in 1988. By then, Lahti had begun to eclipse Turku as the "out-of-town" orchestra to watch. "I worked very hard in Lahti and learned my craft, and eventually there was very little that I couldn't handle. I never expected a huge international career. I just wanted to conduct and do the best I could."

As have the two major Helsinki record companies -- Ondine and Finlandia -- Bis, a Swedish label, has put a great deal of energy into the documentation of Finnish music. The Lahti Symphony's discs for Bis -- particularly the world premiere recording of the original four-movement version of the Sibelius Symphony No. 5 -- brought Vanska worldwide attention and won a Gramophone Magazine award in 1996. The performances were admired for the clarity and polish of the ensemble playing, the downy richness of the strings, the tenderness and incisiveness of the phrasing, and the structural intelligence with which Vanska held everything together.

Slowly, surely, works by Finnish composers other than Sibelius are beginning to enter the repertory. Leonard Slatkin presented the world premiere of Einojuhani Rautavaara's Clarinet Concerto here last month. It was the second piece by Rautavaara, 74, to be taken up by the NSO this year. Last June, Vanska led the composer's "greatest hit" -- "Cantus Arcticus" (1972), a "Concerto for Birds and Orchestra" that combines the taped cries of wild Northern birds with three movements of somber, stately, mysterious and mostly consonant orchestral music. The two disparate elements complement each other, and the results are hauntingly evocative.

Vanska believes especially in the music of Kalevi Aho, 53, who was one of Rautavaara's students and is now a highly versatile and productive composer, supported (as was Sibelius) by grants from the Finnish government. The NSO will present the American premiere of Aho's Symphony No. 9 for Trombone and Orchestra on April 3.

"Aho's music is very difficult," Vanska said, "but difficult in the right way. There are some composers who write difficult music but after half an hour it sounds all the same and you lose interest. Aho keeps you on your toes." He laughed. "When Aho asked our soloist, Christian Lindberg, what were the highest notes the trombone could play, I doubt he realized that Aho would keep him up there all the time!

"And yet in some ways there are a lot of references to the past -- even a part for the harpsichord. In some ways, I would call this symphony old music and contemporary music, all at once."

The second of Vanska's April concerts will feature a rare performance of the Piano Concerto No. 4 in F Minor (Op. 82), written by the 19th-century virtuoso pianist Xaver Scharwenka. "Our soloist will be Stephen Hough, who really believes in this piece -- simply loves it. This is old music that is actually new music -- because nobody knows it."

In between his Washington appearances, Vanska will continue his work with the Lahti Philharmonic, prepare for his tenure in Minneapolis, and guest-conduct throughout Europe and the United States.

"I'm especially proud when I'm invited back to a city," he said. "The first engagement is easy -- after a certain point, any good agent can get you a first chance with an orchestra. The second one you have to win all by yourself."

Osmo Vanska will conduct the National Symphony Orchestra Thursday at 7 p.m. and Friday and Saturday at 8 p.m. at the Kennedy Center Concert Hall. Call 202-467-4600 or visit www.kennedy-center.org.

Conductor Osmo Vanska returns this week to lead the National Symphony Orchestra."By the time I was 12 . . . I never wanted to be anything other than a musician," says Vanska, who will direct the Minnesota Orchestra next fall.