WILLIAMSBURG By tradition, members of the Colonial Williamsburg Fifes and Drums get drummed out of the corps at age 18, the summer after they graduate from high school.

That doesn't necessarily mean their days playing "Yankee Doodle" and "The World Turned Upside Down" are over.

In fact, some veterans of the group never give up the rattle of the snare and the fife's shrill song.

This weekend, about 250 alumni members will gather in Williamsburg to mark the 50th anniversary of the Fifes and Drums, an organization that's come to represent Colonial Williamsburg across the nation and around the globe.

Many of those veterans will pick up their old instruments and play.

"This is very special to me, because I was the corps' first fifer," said 65-year-old Williamsburg resident John Evans Harbour. In 1958, at age 15, the James Blair High School student became one of the corps' original four members. He's never forgotten the allure of 18th-century military music. "The Fifes and Drums are sort of like the Pied Piper," he said. "When people hear them, they naturally move in any direction the music is coming from."

A few months back, digging through a closet in his Kingsmill home, Harbour discovered photos his father shot of the original corps. Harbour believes the occasion was July 4, 1958, and that the picture depicts the group's first public performance.

"When I first saw it, I said, 'My God, that's us!'"

Organizers expect all four original members to attend the weekend's reunion. They'll be joined by as much as a third of the total alumni from the corps' 50-year history. Together, fifers and drummers old and new will march on the historic streets of Williamsburg.

"No other group from Colonial Williamsburg has this kind of loyalty or cohesion -- nobody," said William H. Casterline Jr. "It's really amazing."

A 1969 graduate of the Fifes and Drums, Casterline compiled the group's new official history, "From the Road to Boston to the World Turned Upside Down."

Since Harbour's first pioneering days with the group, the Colonial Williamsburg Fifes and Drums have become a nationally recognized institution, one with its own traditions, rules, heroes and folklore.

In some cases, a stint in the corps is a gift bestowed from one generation to the next. Parents put their offspring on a waiting list for the corps at age 5 -- years before they're eligible to join the ranks. Girls have been admitted since 1999.

Ken Johnston joined in 1967 as a 9-year-old fifer. Now, at age 51, he serves as president of the Fifes and Drums alumni association.

Johnston's son eventually joined the corps and rose through the ranks to sergeant major, the highest level a young musician can attain.

"Being a proud father is fun," Johnston said. "And he's expecting his own son in August, so we're hoping to have a third generation in the corps."

Still, watching from the sidelines wasn't enough for Johnston. Ten years ago, he started a private fife and drum band for alumni who hadn't worked martial music out of their bloodstreams. The Williamsburg Field Musick Fifes and Drums play corporate gigs and special events in Virginia and beyond.

"I started it thinking we would perform a couple of times a month," Johnston said. "We're now doing over 300 performances a year. I've got a lot of college kids who use it as summer employment."

Starting in 1993, the alumni organization has hosted reunions every five years. At Christmas, an alumni corps marches in the Williamsburg Christmas parade.

Lance Pedigo, current drum major for the Fifes and Drums, graduated from the group in 1981, then returned as an employee 10 years later.

When the alumni and the current corps members march in a parade down Duke of Gloucester Street today, spectators will see the largest-ever gathering of Colonial Williamsburg fifers and drummers. Organizers expect more than 350 musicians.

Pedigo will lead that historic parade. What emotions will he feel?

"I'm going to say pride," Pedigo said. "Pride at how far we've come. And I'll just be proud to be marching alongside those same guys again."