The second violin, twisting a few feathery strands of hair around a finger, cast a confiding glance toward the third violin. "God, I hope I don't miss any notes. I'd be so embarassed! He's just such a jamming guy," said Miriam Broady, of Silver Spring, as she nibbled anxiously at her lower lip. Freeing the instrument from under the chin, the 16-year-old Springbrook High School 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, only a few yards from Broady's bow and a gaggle of admiring eyes, more pixie-like than teddy-bear-cuddly, stood master fugel horn player Chuck Mangione. Dressed in his trademark attire a flop 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 from high schools in Maryland, Northern Virginia and the District. "I'm sorry I'm late, but we're 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 an organized group nearly ready to perform a Saturday night concert in Constitution Hall.

"More garlic!" Mangione shouted at the strings section. "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 playing Brahms, Bach and Beethoven -- than Blondie or the Specials, the marathon rehearsal (and another on Saturday morning) moved from a cacophony of clattering cymbals and drums into more recognizable-and melodious-versions of Mangione's "Hill Where the Lord Hides" and "Land of Make Believe."

"Spit 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," Mangione prodded 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 Olympics, athletic events for mentally retarded youngsters, caught Mangione's attention last year when he noticed that his music was used as background for a documentary about the youngsters.

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

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

Just as Crim's face was beginning to relax from its rehearsal 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 all the nervousness, Mangione said, in response to a question about 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 swept across his face.

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

"I bet the swim."

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

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