Samuel Matzner, violist from Arlington, Virginia, member of the 2013 National Youth Orchestra of United States of America, rehearsing at Purchase College, SUNY, 7/2/13. (Chris Lee/Chris Lee)

If you want to fill the seats of your concert hall with young people, put young people on stage. The National Youth Orchestra of the United States, musicians ages 16 to 19, played the Kennedy Center Concert Hall for the first time Saturday night, and the hall was overrun with families, friends, fellow members of the region’s youth orchestras and aspirants.

The NYO-USA, spearheaded by Carnegie Hall, is starting with a bang. It’s good news that Carnegie Hall is putting a lot of money into an outlet for talented young musicians. Money and prestige; the inaugural tour goes from Washington to London and Russia with conductor Valery Gergiev and violin soloist Joshua Bell. The kids — garbed in fire-engine red pants — are audibly thrilled. On Saturday, the orchestra, 120 members strong, presented the sonic equivalent of a Labrador, leaping out into the hall with infectious, woofy, enormous energy.

The hype, though, is slightly frustrating. There are so many significant youth orchestra programs around the country, doing important work, often without much media attention, that it seems unfair to herald this new orchestra as if it was breaking new ground. This was underlined Sunday night, when the Kennedy Center/National Symphony Orchestra’s annual Summer Music Institute Orchestra performed: same venue, same basic talent pool (the SMI’s musicians range from 15 to 20) but a lower-key affair, and admission was free.

Artistically, the difference between the two wasn’t as great as the context might lead you to expect. The NYO has followed the lead of the acclaimed Simon Bolivar Symphony Orchestra — long Venezuela’s national youth orchestra — in its monumental size. That many people playing together results in an impressive sound, even if the strings were slightly woolly at the beginning and there was a touch of callowness in the winds. The SMI orchestra, with 68 members, was lither, lighter and a shade paler. Of course, the groups have different goals: The NYO is focused exclusively on performance, where the SMI musicians (who will perform again July 28) were at the start of a three-week training program with a lot of different components.

The NYO is showcasing American youth with a predominantly Russian program — Tchaikovsky’s violin concerto, Shostakovich’s 10th Symphony — under a Russian conductor. This is supposed to be a gesture of cultural diplomacy, though it seems a little odd; the idea of a Russian tour as a cultural icebreaker smacks of the 1960s. The program did open with a new commission by an American composer, Sean Shepherd. But he, too, sounded the Russian theme in the Russian-inspired festive overture “Magiya,” a lively, bubbling collection of sounds.

The other specifically American element in the evening is Bell. A former wunderkind, he represents the dreams of many of the young musicians around him. And he certainly makes a beautiful sound on the violin, though his phrasing is sometimes overblown and his playing is sometimes careless. At some of the tempos Gergiev took, his rapid passagework got muddy, and at the start of the third movement the orchestra nearly blew the soloist offstage. The whole thing was a tribute to young energy more than coordination.

Gergiev seemed uncharacteristically subdued. Rather than trying to incite the orchestra to new heights of energy as he usually does, he was in the unfamiliar position of needing to restrain it. The Shostakovich 10th, however, was quite fine. It wasn’t exactly a brooding performance, and some of the wind playing throughout the evening was a bit callow, but it had a lot of love and power; the principal French horn played so beautifully that it seemed only appropriate for him to brandish his horn over his head during the ovations, and the concertmaster also was very fine. The encore offered the American touch that may have been lacking: the overture to Gershwin’s “Porgy and Bess,” complete with a banjo solo from a switch-hitting orchestra violinist.

Everything about the SMI orchestra’s event, half the length of the NYO’s, was on a gentler scale. The program paid tribute to two composers celebrating anniversaries this year: Verdi (a dramatic reading of the overture to “La forza del destino”) and Britten (the Four Sea Interludes from “Peter Grimes”). Elizabeth Schulze, a respected and thoroughly competent conductor who has been leading this institute’s orchestra for 13 years, seemed to have spent most of the rehearsal time on Brahms’s Third Symphony, which sounded rich and thoughtful. The Britten, unfortunately, missed the mark; both the emotion and the musical precision were a work in progress. That didn’t really matter, because this performance felt like a chance for gifted young players (and there was some great string playing) to try out new things. The music, Schulze said in comments from the stage, was new to them.

To say that a youth orchestra sounds as good as a professional one is both questionable and meaningless: First, what caliber of “professional orchestra” are we talking about, and second, why expect young musicians to have the experience and finesse of long-term pros? That doesn’t mean they’re not fantastic, just that this is the wrong benchmark.

The orchestra business is a competitive field, but here, for once, competition is beside the point. The SMI and the NYO are both in the business of wanting young players to succeed (and several of last year’s SMI participants are in this year’s NYO). Audiences should keep this in mind, too, and remember, if they’re excited about the NYO, that there’s lots of opportunity to hear playing of this caliber in the Greater Washington area, from the DC Youth Orchestra Program to the National Orchestral Institute at the University of Maryland, all year long.

The NSO SMI orchestra will play again July 28 at 6 p.m. Admission is free.