The second violin, twisting a few feathery strands of hair around a finger, cast a knowing glance toward the third violin.

"God, I hope I don't miss any notes. I'd be so embarrassed. He's just such a jamming guy," said Miriam Broady as she nibbled anxiously at her lower lip. Freeing the instrument from her chin, the 16-year-old violinist strummed a few bars before stealing another peek at the maestro.

"I just feel soooo special. He's cute, just like a teddy bear."

There, in the music room of Robinson High School only a few yards from Broady's bow, stood master fugel horn player Chuck Mangione, more pixie-like than teddy-bear cuddly. Wearing his trademarks -- a floppy hat and T-shirt -- Mangione was flipping through layers of sheet music.

"I hope you're all ready to put up with my madness," Mangione beamed to the 80 young musicians, all specially chosen high school students from Northern Virginia, Maryland and the District. "I'm sorry I'm late, but we've got a lot of work to do in only nine hours."

Several hours and hundreds of bars later, the lithe and wiry Mangione had cajoled, pleaded and shouted his newly commissioned orchestra into a group of musicians nearly ready to take center stage for a Saturday night concert at Constitution Hall.

"More garlic," Mangione shouted at the string session. "What are you guys playing up there? Brahms?

"Come on, play. We don't want any of this Lawrence Welk stuff."

And play they did. For kids who are more accustomed to Brahms, Bach and Beethoven rather than Blondie or the Specials, the marathon practice session (and another on Saturday morning) moved from a cacophony of clattering cymbols and drums into more recognizable, and melodious, versions of Mangione compositions "Hill Where the Lord Hides" or "Land of Make Believe."

"Split it up. I want it loud. I'll take it wrong. I'll take it any way, but if you don't give it to me we can't do anything with it," said Mangione, as he prodded the notes out of the young musicians.

The orchestra came into being last month after 200 area youngsters tried out for the chance to perform with Mangione in a benefit concert for the Special Olympics -- the second such concert Mangione has arranged. The Special Olympics, athletic events designed for mentally retarded youngsters, caught Mangione's attention last year when he noticed that his music was used as background on a documentary about them.

Even though Mangione's compositions are familiar to anyone who watched last year's Winter Olympics in Lake Placid, most of the bejeaned and be-sneakered teen-agers at Robinson High School were seeing the sheet music of Mangione's fusion jazz for the first time.

"It's called hit-and-miss sight reading," said Valerie Crim, an 18-year-old from Woodbridge High School, during a Kentucky fried chicken break.

And just as Crim's face was beginning to relax from its permanent cringe, Mangione was hopping through the aisles of kettle drums and French horns.

"When that hat beats down on you," Crim whispered, "you just pray that what comes out of the cello is what's written on the page."

There's merit to the nervousness, Mangione responded when asked why he chose to perform with the enthusiastic, albeit amateur orchestra, rather than professional musicians.

"This is fun for me, too. But I don't think any of you are challenged enough in your music," Mangione said. "Most kids are under the strange illusion that in the music world you have three months to fool around and get it together before a big concert. But that's wrong, most of the time professional musicians have only about nine hours to prepare.

"There is more to making music than two hours of screaming and yelling fans."

Mangione then raised his hand cum baton and waved his orchestra back into melodies of fusion jazz. A smile flew across his face.

"We're all going to sink or swim together tomorrow night.

"I bet we swim."

And so they did. And in the magic of Saturday night's performance, the group of Brahms fans became true Mangione maestros.

"I love Brahms," mused District resident Alan Cheilek, "but I'd rather play Mangione any day."