The National Symphony Orchestra's Labor Day Concert, held a day late because of rain, was moved indoors to the Kennedy Center last night because heavy concert equipment kept sinking into the damp west lawn of the Capitol.

It could have been a difficult scene if 60,000 lawn patrons had tried to squeeze into the 2,700 seats of the Kennedy Center Concert Hall, but fortunately the audience size nearly balanced the number of seats; there were perhaps 100 empty seats by the time everyone had filed in, a few carrying blankets, picnic baskets, umbrellas, small children and even a backpack or two.

"The bad news is that I don't get to tell you where the comfort stations are," quipped Renee Channey, who cohosted the concert with WGMS colleague Dennis Owens.

Without question, the music sounded better indoors than it would have sounded at the Capitol. But an orchestra spokesman still found it necessary to offer an explanation: "The ground was too wet to support the paraphernalia. Our trucks were sinking in the mud, and we could just see the platform on which the orchestra plays tipping over while the orchestra slid off. We were afraid that the sound towers {the stands on which giant loudspeakers are mounted} would tip over onto the audience." So the audience -- at least some of it -- came to the Kennedy Center and heard the concert of a lifetime.

Andrew Litton, formerly associate conductor of the NSO and now one of the hottest free-lance conductors in America and Europe, took the podium for this concert and also played a bit of piano. In Tchaikovsky's Fourth Symphony, he whipped both the orchestra and the audience to a frenzy. There was prolonged applause after both the first and second movements, and a long standing ovation at the end; the attack on the fourth movement, while the final chords of the third were still reverberating, was too sudden and decisive to allow room for applause.

After intermission, in the complete ballet score "Who Cares?" arranged by Hershey Kay from "The Gershwin Songbook," Litton conducted from the piano keyboard and took several solos, effectively catching the keyboard style of Gershwin himself. In response to a long standing ovation, he came back for an encore -- the smashing piano-and-orchestra arrangement of "I Got Rhythm" that is the score's finale.

At intermission, Evelyn Hagwood of Southeast Washington said that she had found the Tchaikovsky "absolutely fantastic." She was elegantly attired in a flowered dress, but said that originally, at 6:15, she had gone to the Capitol in a slack suit. She asked the police about the concert, she said, and "When they told me it was at the Kennedy Center, I went home, bathed and dressed."

Like Hagwood, many of the people who went to the Kennedy Center are regular patrons of the Concert Hall. But there were others. Jesse Darnell, one of Washington's most devoted concertgoers, reported: "I saw some people outside who asked me how to find the Concert Hall. They had never been here before, and I was glad to give them directions. I like the idea that this concert is bringing new people to the orchestra and to the Kennedy Center."

On Sunday, when the concert was postponed because of rain, Darnell had gone down to the Capitol. "I didn't hear that they had canceled it, and I live nearby," he said. "But I'm glad they moved it in here; the sound is so much better."

One pair of newcomers at the Kennedy Center were Cheryl Klinker and Anthony Aegerter, a couple from Seattle on a 10-day vacation in Washington. "My husband heard something on the radio and said, 'Hey, there's a free concert; let's go,' " said Klinker. "So here we are."

Susan and John Byram came with their parents and two daughters, Laura and Melissa, who are 2 and 4 years old. How did they keep the girls quiet? "We fed them M&Ms -- anything we could get our hands on." Susan is a piano and voice teacher, so the girls are not exactly unaccustomed to live music.

Out on the Terrace during intermission, Kirk Lewis of Alexandria was discussing some fine points of the Tchaikovsky with a couple of friends: the way timpanist Fred Begun "pulled" some of his strokes for special effect; the sound of massed strings playing pizzicato in the scherzo; the impact of indoor compared with outdoor acoustics.

A regular patron of the orchestra and the Kennedy Center, Lewis was happy that the concert had been moved indoors. "I remember a 1983 choral concert conducted by Robert Shaw that was moved indoors at the last minute," he said, "and the music was great. The best concerts seem to come when they change at the last minute."

Besides the improved acoustics, he said, he likes indoor concerts because "You can get close enough to watch the conductor." Litton was worth watching, not only for his baton technique but for his reaction to some of the outdoor atmosphere that the audience brought indoors. Nobody brought pets to the Concert Hall, and nobody was detected eating, sipping wine or smoking during the concert as they do routinely at the Capitol. But there were quite a few children, and some of them indulged in self-expression that could be heard occasionally during quiet passages -- not necessarily crying; many of the noises sounded happy.

At one point during the Tchaikovsky symphony's scherzo, when the orchestra was going along smoothly and the children were particularly audible, Litton did a three-quarter right turn on the podium, not missing a beat with his baton, and slowly, thoroughly scanned the audience. The audience noise subsided, and Litton turned back to the orchestra, which had continued smoothly. Then there was a new outburst of audience noise -- this time, adult laughter -- which he simply ignored. It was frenzy time in the music, and he built the final music to an overwhelming climax. The orchestra and Litton are old acquaintances, and he coaxed it into playing at a level of energy and precision that it reaches only on special occasions.

In the 16 short numbers of "Who Cares?," which include orchestral arrangements of such Gershwin standards as "Strike Up the Band," " 'S Wonderful," "Lady Be Good," "The Man I Love" and "I Got Rhythm," orchestrator Hershey Kay often captures the special sound of dance bands and pit bands of the 1920s and '30s. Litton and the NSO realized that sound effectively, and with such market-tested melodies the audience's long ovation and demand for an encore were practically foregone conclusions.

THE 'WHO CARES?' CD

After last night's performance of Gershiwin's "Who Cares?" at least 1,000 Washingtonians this morning must be wondering where they can get the recording It is part of an all-Gershwin recording taped last March in London, issued by the Royal Philarmonic Orchestra on its own RPO label (CD, RPO 8008) and reportedly available in Washington.

Besides "Who Cares?" in which he conducts the RPO and plays the piano, Litton also plays the four solo piano numbers from "The Gershwin Songbook" that Hershey Kay did not orchestrate, and he is the conductor and piano soloist in the original jazz-band arrangement of "Rhapsody in Blue."

He is first-class throughout, as pianist and conductor. A special strength of his piano playing is his ability to phrase the music like a good jazz singer -- to make the piano "breathe." This is particularly notable in "Rhapsody in Blue," a dazzling performance.