"We were brought up in his home, and each of us had to learn to play at least two instruments," recalls Percy Humphrey, the 80-year-old leader of the Preservation Hall Jazz Band, of his grandfather. "I happened to select drums first, and then commenced playing cornet. I finally dropped the drum situation and stuck with the trumpet -- I got stuck with it, anyhow, and I'm still trying to play the trumpet," he laughs.

Percy's brother, clarinetist Willie Humphrey, who will be 85 in December, also has memories of James B. (Professor Jim) Humphrey, one of the most distinguished music teachers of New Orleans. "He had his system -- he branded us and if we didn't do right, he would put it, well, we could better understand on our backs," chuckles Willie Humphrey fondly.

In the 1890s Jim Humphrey, attired in swallowtail coat, would take the train out to Magnolia Plantation to instruct the farmhands in the rudiments of music and, his brother says, "they got to have a little brass band and have a little amusement." The formally trained Humphrey, who died in 1937, saw many of his prize pupils, including a son and three grandsons, swept up by the new music that came into being around the turn of the century. Among those he taught were trombonist Kid Ory and trumpeters Papa Celestin and Chris Kelly. "They didn't give him credit for it," avers Percy, "but he didn't worry about that, he taught so many. All he wanted to do was to help others learn something, help them make a living, that's all."

Percy and Willie Humphrey will return to Wolf Trap on Sunday, July 21. It's an anniversary of sorts, for the Preservation Hall Jazz Band is one of only two acts to play Wolf Trap every season since the park's opening in 1971. (The other is the National Symphony Orchestra.)

As part of a tradition that reaches back several generations, the Humphreys are concerned that it continue. Percy, who has resided in his native city of New Orleans all his life and is considered one of its finest brass band trumpeters, and Willie, whose early association with jazz pioneers Tony Jackson, King Oliver, Freddie Keppard and others took him to Chicago and to St. Louis in the '20s, are confident that their music will live on. "I noticed so many youngsters trying to develop it," says Percy, "the foreigners and the Americans, trying to fall right in our footsteps."

The band's sousaphone player, Allan Jaffe, who with his wife Sandra founded Preservation Hall in 1961, has given much thought to the subject. "I always think that the reason that this music came about is first there was a need, and then the music came to fill it," says Jaffe. "New Orleans jazz is a functional music and is still being played in churches, still being used at funerals, at Mardi Gras time and to open a new store. It is so suited to all of these needs that it's not the music of a period, it's really the music of a city and it's as current as the day on which it's played. It's modern, contemporary music because it has a modern, contemporary use. As long as the music can have a contemporary use and be functional and effective, I think it's going to continue."

That the tradition is still very much alive in New Orleans is attested to, insists Jaffe, by some new developments. He points to the formation in recent years of such bands as the be-bop-flavored Dirty Dozen Brass Band, which have "taken the tradition that already exists and come in with a totally new approach still serving that tradition. They play for funerals and parades the same as the Olympia and the Eureka bands.

"There's been an awakening in the black community during the past 10 years that people who want to be professional musicians can be playing New Orleans jazz as their fathers and grandfathers did and make a living at it," Jaffe adds. "New Orleans is the only city that I know of where you ask a little kid what he wants to be, and instead of saying, 'I want to be a fireman' or 'I want to be a policeman,' he says, 'I want to be a musician.' "