Once in a lifetime, the road to Carnegie Hall starts . . . in a county school board parking lot off Rockville Pike.

There, two charter buses wait, along with 100 accomplished

musicians -- some bleary-eyed and tired from a weekend of high school and after-prom parties. A few dozen parents are on hand for the send-off, as a conductor-cum-master sergeant supervises the critical business of loading instruments. "Basses first," she directs.

In exactly 12 hours, conductor Olivia Gutoff and those musicians, teenage members of the Maryland Classic Philharmonic Youth Orchestra, will be in the country's most celebrated concert hall, awaiting their cue to go on.

This is not a Cinderella story, per se. In the orchestra's 56-year history, it has performed in Switzerland, England, Wales and Austria. For two decades, it has played every Christmas Eve at the Kennedy Center. It has sent graduates on to prestigious schools such as the Juilliard School and Curtis Institute of Music, and in several years the Philharmonic group and its younger siblings -- a junior orchestra, prep orchestra and string ensemble, more than 350 students in all -- will become permanent residents in the new multimillion-dollar Strathmore Hall Music Center in Bethesda.

Still, the pinnacle of any classical musician's career is that building at 57th Street and Seventh Avenue in New York City. And on Sunday, the Maryland Classic Philharmonic Youth Orchestra found itself backstage, poised for its Carnegie Hall debut.

But first was practice, practice, practice. And that bus ride.

Final rehearsal,

four days to performance:

"Let's have an A."

Like every Wednesday evening, this one officially begins with an A note. Gutoff, clad as always in slacks and sneakers, is a demanding, no-nonsense leader, although she has an almost impish laugh in lighter moments. Tonight's two-hour-plus rehearsal will include several of those moments. While facing a technically demanding program in New York, the group is down to fine-tuning -- a little bit more pianissimo here, a tad more mezzo forte there.

The students run through the opening of their initial piece, "Passacaglia on a Well-Known Theme" by English composer Gordon Jacob, and not too many measures after the first crash of cymbals, Gutoff cuts them off.

"Bravo, very, very good, excellent," she says. "That sounds terrific. Let's turn that over."

Nearly six months earlier, in the boxy, low-ceilinged cafeteria at Herbert Hoover Middle School, where the Philharmonic orchestra rehearses weekly, lunch tables pushed up against the walls, Gutoff had stood before them and said she had something to discuss. The year had been something of a letdown: A potential trip to China had been scrubbed, and then a tour in Italy, with deposits already collected, was canceled for safety reasons in the wake of Sept. 11.

"How'd you like to play a concert at Carnegie Hall?" Gutoff asked. She enjoys her memory of their reaction. "They looked at me, incredulous."

The way the invitation came about is testament to the strength of the entire MCYO -- as members and their parents shorthand its name in conversation. "Their reputation is that they are very, very good," says Carole Wysocki, who, as manager of the National Symphony Orchestra's education program, has reason to know. Every year for the past half-dozen, numerous MCYO students have been selected to perform with counterparts from across the country in a special program at Carnegie Hall. The most recent was conducted by the world-renowned Lukas Foss. Of the 82 young musicians before him, 31 hailed from Montgomery County.

Even aside from last fall's trip disappointments, it was fitting that the 2001-02 Philharmonic orchestra would mark this official debut in New York. It has been an extremely proficient group, technically and musically, says Gutoff, 63, conductor and artistic director since 1994.

"But more than that is this chemistry that [they] have that, honestly, you can't cultivate." An energy, a dynamic, she explains.

Despite her own long career teaching and playing French horn, "I can't put my finger on it. I just know I'm extremely lucky to be involved in it."

Though the majority will continue pursuing music only as avocation, some members hope to make it their professional career. Violinist Reinaldo Moya, 17, a Philharmonic from Quince Orchard High School, fills the role of orchestra funnyman yet wants to be a conductor one day.

"It's my passion," he says. "It gives you the whole picture of the music."

At this point, their lives also are busy with much more. These teenagers include Intel science competition semifinalists, National Merit scholars, club presidents, track stars. "These are brilliant students," Gutoff says.

The demands show by late spring. Many snatch precious minutes of study time during rehearsal breaks. Two students confer about their upcoming Advanced Placement chemistry exam; another keeps a macroeconomics study book near her viola case. Their whirlwind journey to New York will be squeezed between more than Philharmonic proms and graduation. For a number of the juniors and sophomores, the day before means SAT and SAT II exams.

After a long school day, the members yawn during rehearsal interludes. They hardly look classical in their shorts, T-shirts, flip-flops; one strings player wears his baseball cap backward, and his black fingernail polish matches the rest of his attire.

When Gutoff signals, however, they are ready. Well, most of the time.

"If each of the entrances could be a smidgen louder," she suggests during the final practice of the third of their five Carnegie Hall selections, a composition the MCYO commissioned several years ago from retired National Symphony violinist Andreas Makris. "Antithesis" offers frenzied, stop-start measures; an exotic blend of strings with melody, conjuring Makris's native Greece; and booming brass.

Gutoff raises her baton -- and the entire strings section misses its entrance.

"That was incredible!" she grins, twirling in empty air as laughter bounces around the room. "The best you've ever done. Everyone was all together."

Adds one wiseguy up front, "And no wrong notes."

The New Jersey Turnpike,

10 hours to performance:

The two buses pulled out at 8:14 a.m. Sunday, parents waving goodbye from the parking lot. ("I've told everybody," admitted Jay Spencer, mother of 15-year-old David, a sophomore at Richard Montgomery High School. The ponytailed percussionist is assigned the triangle during "Antithesis." "Even the triangle player is going to Carnegie Hall.")

By 11 a.m., they are rolling north on the turnpike. In Bus 1, a French horn player had the foresight to pack entertainment, and so the Disney flick "Mulan" is showing on the video monitors. Despite the noise, some students are reading. One trumpeter is asleep, face buried in a red pillow. In the back, the drummers hang together and maintain a banter. A 19.5-ounce box of Corn Pops is passed back and forth. Except for the sporadic interlude -- the first notes of "Passacaglia," hummed -- they could be traveling to Kings Dominion.

Many in the orchestra have been together two years or more, some from their time in the junior orchestra during middle school. But outside of their own sections, they tend to know each other more by instrument than by name or background. During fall rehearsals, "every week we [would] pick out a person we've never seen before," remembers 16-year-old flutist Samantha Hong, a junior at Montgomery Blair High School.

Few may know, for example, that when Moya arrived from Venezuela in 1999 he spoke virtually no English. Or that, for principal clarinetist Diane Minerbi, 17, her position this year was a rewarding triumph.

The Churchill High School Philharmonic had auditioned the previous year and blown it badly, with tears and despair.

"I went in there and just totally messed up," she says. She called Gutoff afterward for advice, then took her words to heart: For 12 months, "I practiced harder than I ever had." And the next time Minerbi auditioned, as Gutoff puts it, "from beginning to end it was flawless."

Likely the most recognizable face and name is concertmaster Rahul Satija. The slight, intense 16-year-old, a Philharmonic at Montgomery Blair High School, first picked up a violin when he was 2.

He may not major in music in college, but he identifies himself first and foremost as a musician, and his position this year offered much visibility. It also demanded responsibility.

"All the bowings, all the fingering, the phrases, need to be coordinated," he says. He had to come late recently to rehearsal and listened from the sidelines as the strings practiced. Perfect, he thought.

"Absolutely it's been fun," says Satija. But even more, "it's been gratifying."

Just after noon, the Manhattan skyline appears on the horizon like a bluish mirage. The bus chatter falls quiet. Figuratively speaking, Carnegie Hall is in sight.

Orchestra Room 1,

30 minutes to performance:

Even with all the preparation and reminders, there have been a few glitches. None too serious: an oboist who forgot his black shoes and socks, a bass player who left behind her concert blouse. To the rescue came the mothers and fathers (and grandmothers and siblings and cousins) who arrived later in the afternoon on the two parents' buses that MCYO also rented for the performance.

By now, they are in place in the soaring hall, listening to the first of the three orchestras appearing tonight. MidAmerica Productions Inc. puts on this Ensemble Spotlight Series; during its two decades, MidAmerica has brought only two other Maryland high school instrumental groups to Carnegie Hall, and none from Virginia or the District.

Waiting in Orchestra Room 1, the Montgomery County musicians can hear the El Paso orchestra midway through its last number, Rimsky-Korsakov's "Capriccio Espagnol." They begin lining up, again basses first. The mood is muted, nervous. They know how good the acoustics are in this storied space. Every instrument can be heard. So, too, can every mistake.

"I never thought I'd be walking on stage at Carnegie Hall," Kathryn Murphy, 15, a freshman violinist from Walt Whitman High School, says in an awed tone.

Applause sounds as the Texans conclude. The door opens and Gutoff, pants exchanged for a long black dress with gold sequins, signals them to begin up the stairs. She already has given them her final instructions.

"In the vernacular of show business, break a leg," she had exhorted. "But be expressive."

Onstage, 9 p.m.:

The orchestra is seated. There is silence, and suddenly Satija appears, threading his way through the strings. He faces his colleagues to play an A. The sweet discordance that is musicians tuning follows.

They are ready, and now Gutoff is making her way to the front under the gilded proscenium. The hall is well filled into the third balcony, even with top tickets costing $75 apiece. Again there is silence, so that the first notes of "Passacaglia," a marriage of harp and French horn, hold forth with beautiful clarity and resonance.

For more than 40 minutes, these young musicians have the spotlight. Satija stands alone during the second piece and offers a slow, tender solo with string orchestra accompaniment. He finesses a difficult octave shift, draws out the final note so gently that it seems to float upward like a feather, and after a split second the applause is loud and sustained.

But the end provides the biggest surprise, after the ultimate chord of the finale of Tchaikovsky's Symphony No. 5 in E minor, as Gutoff turns and the orchestra rises for its bow.

In the hall, most of the audience is rising, too. To give the MCYO a standing ovation.