The National Symphony Orchestra's intriguing all-Russian program last night in the Kennedy Center's Concert Hall was by turns entertaining and instructive--Liadov's Eight Russian Folk Songs, Tchaikovsky's Violin Concerto (played by 14-year-old violinist Yura Lee) and Shostakovich's Symphony No. 15.

The 15th Symphony, the composer's last, clearly presents the most fundamental and recurring question surrounding his extensive legacy of symphonic exploration: Is this symphony more than the sum of its masterly orchestration? Put differently, is Shostakovich pulling strings, putting us on, tub-thumping, drawing us into a hermetic box of cynicism deriving from a lifetime of censorship from the Soviet Realists? Leonard Slatkin conducted excerpts from the symphony and then, from the podium, addressed the heart of the matter, saying that Shostakovich ultimately concluded "there is nothing new in music. All we can do is take what came before and recycle it."

Slatkin's remarks were prompted by a valedictory symphony that begins with an aimless little flute ditty, which then gathers force from the strings and, seconds later, turns into the cantering melody from Rossini's "William Tell" Overture--the "Lone Ranger" theme whose banality Shostakovich recognized just as we do. It circles, threatens to transform, assumes mocking power and dominates the first movement. Surely Shostakovich is saying something about his compositional process--otherwise, all we have is literally a bit of horseplay--but this music is intended to discomfit, and it makes even the most casual listener wary of what is yet to come.

What does come, among much else, is a plethora of quotes and near-quotes from Shostakovich's own music, references to Wagner and any number of passages that suggest other composers (Richard Strauss, Haydn, Mahler). But the jaunty solipsisms of the first movement do not return, and from the plaintive, funereal melody of the second movement, the symphony somehow generates increasing interest and cumulative power. Whatever its value, this is music that holds the ear.

It isn't easy to conduct but Slatkin had the NSO under tight control: The massive brass choirs never disintegrated into shrillness, the strings had a precision unusual for edge-of-the-repertory ventures, and the dynamic line in the slow concluding movement was finely judged. As this palimpsest of a symphony faded into stillness, it yielded no easy secrets, but one had the sense that they are deeply interior and worth exploring.

Lee, the soloist in Tchaikovsky's Violin Concerto, took the first movement just a bit slower than usual, and it was less overtly virtuosic, but along the way she made one aware of telling structural details. Her tone is big, well-centered and boldly expressive, and she did not lack steel in projecting the concerto's larger-than-life theatrics. Lee is an immensely talented young artist whose musical personality will become bolder still in the years to come.

The Liadov Folk Songs are miniatures loaded with modest but wholly fetching charm. Revival of this neglected score is long overdue. Slatkin conducted with altogether appropriate affection.