By CLAYTON PARK

Bob Flick, a Ballard High School alumnus (class of 1956), owes a debt of gratitude to his high school choir director.

Harriet Charlton's insistence that her students learn proper singing techniques and correct posture proved invaluable to Flick when he later teamed up with three fraternity brothers at the University of Washington to form a folk-pop music group called The Brothers Four.

The quartet, known for their sweet harmonies and acoustic, string-driven sound, recorded several hit records for Columbia Records in the early '60s and continue to perform concerts around the world, with strong fan followings in Europe and Asia even to this day.

On Saturday, May 18, Flick will repay his "debt" when he and his band returns to his high school alma mater to perform a concert to celebrate Ballard High School's 100th anniversary. Proceeds from the concert - which will conclude a weekend of festivities including an all-class reunion of Ballard grads - will benefit the school's media lab.

"This is a real special occasion," said Flick, who recently spoke with the Seattle Sun. Flick said he has fond memories of growing up in the Ballard neighborhood, where he attended Whittier Elementary and Monroe Junior High School in addition to Ballard High - all within walking distance of his family's home.

While he took piano lessons as a grade school student, and sang in the high school choir at Ballard, Flick said becoming a folk music singing sensation was never his aspiration growing up nor was it what he had in mind when, as a freshman at the UW, he teamed up with guitarist John Paine, guitar and banjo player Mike Kirkland and guitarist Dick Foley to form The Brothers Four. Flick decided to learn to play bass to fill out the group's sound.

Flick said the band never considered themselves folk singers in the purist sense. They simply enjoyed singing and playing acoustic instruments with the goal of entertaining their audiences. "We're folk-POP singers. We didn't come from coal mines or cotton fields," he said. "Singing was just a thing that you did in fraternities and sororities," explained Flick in a biography posted on the band's Web site, www.Brothersfour.com. "A lot of guys sang - we just happened to have instruments, too, so we became a band."

Make that a band in the right place at the right time.

Thanks to the success of the Kingston Trio's hit tune "Tom Dooley," Columbia Records began looking to add other "folk" acts. In 1959, the record label signed The Brothers Four to a recording contract, which paid off the next year when the quartet scored a chart-topping hit with their recording of "Greenfields." The band also scored big by recording "The Green Leaves of Summer," which would be featured in the soundtrack for the John Wayne movie "The Alamo."

The Brothers Four also proved to be popular draws in concert, which earned them an invitation to play at the inauguration of President John F. Kennedy, and numerous television appearances, including the Ed Sullivan Show. On a couple of occasions, Flick and his bandmates were paired in concert with a young troubadour named Bob Dylan.

The Brothers Four also once opened for The Beatles, in a charity benefit concert in New York City. Flick recalled riding the elevator with the Fab Four, but said, other than that, "all I remember is a bunch of screaming girls who were obviously there for The Beatles."

While their days as chart-toppers have long since passed, The Brothers Four continue to tour and occasionally put out new albums, some of which are only available overseas. The band's latest U.S. releases were two albums issued in 1999 by a record label called Folk Era Records. Over the years, the band has had some changes in personnel. The current lineup features Flick and Paine, along with Terry Lauber on guitar and mandolin, and Mark Pearson on guitar and banjo.

The Brothers Four recently performed two sold-out shows with the Kingston Trio in Washington, D.C., and will perform again with the group in a few weeks, along with other '60s folk acts: The Smothers Brothers, Judy Collins and The Limelighters. The show, titled "This Land is Your Land," will be performed in Pittsburgh and filmed to be aired as a television special on PBS this fall.

When asked how long The Brothers Four plan to keep performing as a group, Flick said, "We'll keep on doing this as long as we're asked."