It has taken 75 years for Washington's National Symphony Orchestra to become truly national, but it has finally accomplished this in high style. The orchestra's first-ever transcontinental runout -- five concerts in California running through Monday, plus two in Nevada -- began Wednesday night with an all-American program at Los Angeles's new but already legendary Walt Disney Concert Hall.

A capacity audience cheered a program that would hardly rank as the usual touring-orchestra easy-listening fare. Even the closing encore, "The Star-Spangled Banner" in the tricky contrapuntal reworking by Rob Mathis, came as something of a surprise. (Didn't Igor Stravinsky once get arrested for perpetrating that kind of rearrangement?)

If Los Angeles counted as a first-time visit for the National Symphony, it ranked as just the opposite for conductor Leonard Slatkin, who is very much a hometown boy. His parents, violinist Felix Slatkin and cellist Eleanor Aller, were founding members of the renowned Hollywood String Quartet, whose concerts and still-available recordings represent classical excellence. Both parents were also active in studio orchestras in Hollywood's musical heyday; Leonard on his own has been a frequent participant in Los Angeles's musical life, most recently at the Hollywood Bowl. It was high time, therefore, for him to be showing off his own band to the folks back home.

This he did Wednesday night. For the orchestra, of course, the principal interest was the experience of Disney Hall, with its intimate design in welcoming, warm-hued wood and the remarkable acoustic design that brings everything on stage vividly to life. Caught on the run, only a couple of hours after landing in Los Angeles, between an afternoon rehearsal and a pre-concert audience warm-up, Slatkin had particularly kind words for the hall's resonance, "the way orchestral sounds make themselves heard. We've tried to make those changes in our own Concert Hall," he went on, "but we've got some distance still to go."

"A special quality," echoes cellist Glenn Garlick, "is the way the sound melds into a whole. I hear things in the brass that I've never heard before." Adds principal contrabass Robert Oppelt: "I've noticed how lush and rich the cellos sound here." One further advantage, notes violinist Paula Akbar, is that "I can see the conductor better."

At my accustomed perch in Disney Hall, from which the sounds of the Los Angeles Philharmonic's Beethoven Festival in recent weeks have been as audible honey, the opening summonses of Leonard Bernstein's "West Side Story" dances came as the jolt they were intended to deliver. Given the limited time the National Symphony had to really "learn" the hall -- the L.A. Phil is only now, in its third year, really settling in -- Slatkin drew from these tidily orchestrated vignettes a fine, bright sense of theater.

Next came music of lesser substance perhaps, but no less endearing. These are lean years for Samuel Barber's music, among much of the critical fraternity at least. The opera "Vanessa" is continually revived and continually shot down; nobody seems to know what to do with the grander "Antony and Cleopatra"; the beautiful Adagio circulates in a wretched choral version; the Violin Concerto is merely tolerated, and everybody jeers at its finale, which is too short and therefore regarded as trivial. Itzhak Perlman's playing of that work on this occasion was truly rhapsodic, elegant and, in the finale, both demonic and delightful. Slatkin had reduced the orchestra to just the right chamber-ensemble size. It was the evening's best music, and by some measure the best performance.

Finally there was the First Symphony of John Corigliano, which has earned both the composer and Slatkin their Grammys and their international huzzahs and which, as Slatkin told the audience twice at Disney (at the pre-concert talk and again from the podium), has earned more performances in its 15 years than any major work in the last whatever. It is possible to believe all that, and it is also possible to accept and believe the sincerity of the premises on which the work was written -- the deaths of beloved friends, the horrors caused by the AIDS epidemic here and abroad -- and still find the music shallow, contrived, agonizingly protracted and, at many junctures, ugly beyond recall. That Slatkin, along with others, does not find it so is what gives his performance its strength -- at Disney Hall on Wednesday night and on his much-honored recording. He's entitled.

Itzhak Perlman invigorated the Walt Disney Concert Hall with his riveting interpretation of Samuel Barber's Violin Concerto during the NSO's first performance in Los Angeles.