Later pictures of Jean Sibelius's big bald head make it look like something a glacier might churn up: round and elemental and, like a boulder, indifferent to the lichen growing on it and winds and rains beating against it. His music, including the monumental Violin Concerto, which the National Symphony Orchestra performed last night at the Kennedy Center Concert Hall, is like that, too.

There are people--and not just sentimental Finns devoted to their great national genius--who make the Sibelius Violin Concerto a kind of hobby or career, attending every possible performance, collecting every possible recording (and there are many, many of them). Like Mahler's Symphony No. 2, it collects not just listeners, but adherents. More than, say, the violin concertos of Mendelssohn and Bruch, it is an evening in itself, with so much musical and emotional substance that it takes longer to digest than it does to play.

Especially when Joshua Bell is the performer, as he was last night. The 31-year-old American violinist with movie-star good looks has emerged as one of the finest musicians of his generation, a serious artist whose interpretations can be seriously set beside and favorably compared to players twice his age. Dead players, too. Last night, there were moments of such interpretive precision and musical focus that his playing was reminiscent of Heifetz's. The reading was sober, with adamantine rhythmic control, and filled with transcendent inconsolability.

Bell's violin, a 1732 Stradivarius, made Lauren Bacall-like noises in its lower register, giving the solo line's distinctive, throaty cries a sense of clawing painfully at the cold air. At its top, the violin's tone is pristine, neither warm nor cold, but dazzlingly limpid. Bell's control over the technical challenges of this extraordinarily difficult work never pushed the violin's tone anywhere near the strident. The instrument sounded as confident tonally as the soloist.

Bell has recently recorded the Sibelius with the Los Angeles Philharmonic, a disc due out after the turn of the year. If the interpretation he gave last night with the NSO, under the baton of Stanislaw Skrowaczewski, is anything like the one he has recorded, it will be a disc to be reckoned with. If the Los Angeles Philharmonic rewards him with a more lustrous and integrated accompaniment than that of Skrowaczewski, it will be a very fine recording indeed.

Skrowaczewski led an orchestra fresh from a well-received national tour (with an insert in the program documenting several good reviews to prove it). At 76, the Polish-born composer and conductor is no doubt remembered differently by the various generations that have experienced his music. He has spent years as a composer, then as a conductor--for 19 years at the Minneapolis Symphony--and now as a vibrant old lion of the guest-conducting circuit.

Last night he performed one of his own works, crafted in the 1960s from musical material dating from his period as a relatively aggressive, modern composer in the 1940s. "Music at Night" opened the program with a study in clenched fists, stark gestures and granite orchestration.

As with the works of many composer-conductors, its principal strength lies in the masterly handling of orchestral timbres. But it is music of protest that lacks a clear agenda. Why, indeed, is this piece so grim and acerbic? There is plenty of fury and nastiness in the world, and it too deserves expression in music, but other composers have done it with significantly less strenuousness and much more compelling drama.

Skrowaczewski also led the orchestra in Beethoven's Symphony No. 3 ("Eroica"). Beethoven goes about his business very methodically in this work, and Skrowaczewski did little to speed it along. The performance sounded like what one might have expected from a good regional orchestra in the middle of this century: confident, assertive, but rather too much in the shadow of Toscanini's over-rhetorical readings. It did, however, hit all the heights, there was fine humor in the opening of the fourth movement, and the horns played reliably and with exuberance in the Scherzo. Reliable Beethoven, but not earth-shattering.