Like many Americans of my generation, I first met Pete Seeger through his music. I learned "This Old Man" in kindergarten. As a teenager, "If Had a Hammer" played on my transistor radio. And as the Vietnam War and civil-rights movement convulsed the nation, I marched in protest to the verses of "We Shall Overcome" and "Where Have All the Flowers Gone?"

Then I got to know him in a more personal way. On Oct. 15, 1971, I set foot for the first time on Clearwater, the 106-foot traditional wooden sailboat he had helped to conceive and build, and which became a part of his lasting legacy.

Modeled on the great gaff-rigged sloops that plied the Hudson River in the 18th and 19th centuries, Seeger envisioned Clearwater as a way to rally the people of the Hudson Valley, where he made his home, to the new cause of environmentalism.

Seeger was not on board the morning I caught my first whiff of her tarred rigging and hemp ropes and wood-fired cookstove. (He came aboard briefly later in the trip.) But, as I wrote in an Inquirer Magazine article years later, I had stepped unwittingly that day into the moral universe of Pete Seeger: "a rustic, collective, optimistic, egalitarian, not-for-profit universe" reminiscent of the Shakers and other 19th-century religious communities.

I became a part of her permanent crew, and for the next few years helped sail her from town to town for dockside folk concerts, or taught visiting schoolchildren about the marine life struggling to survive in the polluted Hudson. These were the happiest days of my early adulthood, filled with laughter and friendship and music, all in the name of cleaning up the Hudson.

Seeger didn't sail with us often. Instead, he'd stop by when we were close by his home town of Peekskill, N.Y., to drop off home-made bread, wash dishes, or spend an hour chopping firewood. Often as not, he'd then pull out his famous five-string banjo - with the words "This Machine Surrounds Hate and Forces It to Surrender" penned on the soundboard - and start us singing.

He was a private man, however, who often hid in public behind a wall of words. As I got to know him better I sometimes drove him to concerts or visited him and his wife, Toshi, at the log cabin they built overlooking the river. Still, his talk was often of billionaires and their "corrupting ways," and how the future of the planet depended on little nonprofits and small businesses and communes.

Crucially, though, Seeger lived his values. Once, without recognizing me, he picked me up hitchhiking on a busy highway. And when Toshi and I arrived one day at the cabin at 1 a.m., Pete emerged from the house in his pajamas to open the car for her. He sang for little or no charge for any (liberal) worthy cause, drove drab cars, lived frugally, and answered all his mail - including the letter my 10-year-old son, Chris, wrote to him years ago, telling him how much he liked his music.

"I'm a lucky oldster to have friends like you," Seeger wrote back. And under the hand-drawn banjo he penned some subversive advice: "Don't let your schooling interfere with your education."

Now 24, Chris works as a shipwright and crew on Clearwater, where he, too, has found much in the moral universe of Pete Seeger. From him, through Clearwater, we both discovered a sense of community and worthy purpose, for which I am enormously grateful.

I last saw Pete Oct. 26 at a memorial service for Toshi, who died in July. He was frail, and I wondered how long he would last without her. Not long, as it turned out. But - as he reminded us so eloquently in his famous song "Turn! Turn! Turn!" - there is a time to die, and his time is come.

He was my hero.