In 1969, Eric Bogle, a high school dropout, sometime accountant and former singer in a Beatles-style band, emigrated from Scotland to Australia in search of money and adventure.

Before the move, he had started writing songs somewhat like the ones his grandfather, a noted Scottish balladeer, used to sing. But nothing amounted to much.

Then in 1971, with Australia embroiled in Vietnam alongside the United States, Mr. Bogle sat down to write what would become one of the most admired songs about war: "And the Band Played Waltzing Matilda."

"I wanted to write an antiwar song but didn't want to denigrate the courage of the soldier," Mr. Bogle recalled in an interview on Wednesday before a show at the Manhattan nightclub Satalla. "There was too much of that 'baby killer' stuff going on."

Now 61, he is the archetypal touring folk singer, burly and balding and bearded, with a remarkably similar-looking sideman, John Munro, and a repertory ranging from wrenching to raunchy. (One song tells the tragic tale of Gomez, an amorous Chihuahua who meets an untimely end when he tries to mate with a Saint Bernard.)

But at every stop, the audiences, many having grown gray along with Mr. Bogle, await the tune he wrote 34 years ago.

On Wednesday night, he told the roughly 100 listeners how sometimes "a song acts as a key that opens a lot of doors," adding, "This was my key."

In it, he chose to tackle current events by exploring historical ones - a habit he has had ever since - and jumping back to Australia's first real battlefield test: in Gallipoli, Turkey, in 1915, just 14 years after the Commonwealth of Australia was born.

The song is in the voice of an innocent rural lad who joined the Australian and New Zealand Army Corps, or Anzac, in 1915, was handed a tin hat and a gun and was shipped with 17,000 others to the killing shores of Suvla Bay, where they were "butchered like lambs at the slaughter."

The refrain recounts how at every turn - when troops were dispatched, when the maimed came home, when the dead were buried, when the dying veterans marched - some martial band played "Waltzing Matilda," the unofficial Australian anthem.

The song, almost independent of Mr. Bogle's career as a folk performer, took on its own life as an antiwar standard.

In a telephone interview from his home in Beacon, N.Y., Pete Seeger called it "one of the world's greatest songs."

"In a few lines of poetry he captured one of the great contradictions of the world: the heroism of people doing something, even knowing it was a crazy something," Mr. Seeger said. "And he showed how the establishment has used music for thousands of years to support its way of thinking."

When it was recorded in Ireland by Liam Clancy and Tommy Makem in 1976, the song became the first of three chart-topping hits for Mr. Bogle there. It was later recorded by the Irish punk-folk band the Pogues.

Why such resonance with Ireland? "The Celtic people are a highly emotional bunch, as we all know, God bless them," Mr. Bogle said. "And my songs are based on pure emotion, most of them."

His last American visit was in 2002, and he is wrapping up a two-month tour in the next three weeks, including a performance tonight at the Central Unitarian Church in Paramus, N.J., and on Nov. 13 at the Towne Crier Cafe in Pawling, N.Y.

His songbook is as variegated as folk music itself (details are at ericbogle.net). Songs range from a searing account of an apartheid prison hanging to a satirical romp on the nasal style of Bob Dylan and audiences' persistent habit of asking Mr. Bogle to play a Dylan song. (He doesn't play any.)

There is a relentless juxtaposition of humor and horror. He began the Manhattan show with a vaudevillian introductory song alluding to his age: "We're on the road, so lock up your grannies." But he returned inexorably to war, as he painted wrenching word pictures of children blasted by bombers in Baghdad and, in another song that became an Irish hit, explored the sacrifice of Pvt. Willie McBride, one of 310 men buried in a 1916 battalion cemetery Mr. Bogle visited in northern France in 1975.

In that song, written as "No Man's Land" and also known as "Green Fields of France," Mr. Bogle dwells again on how music is used to salve the wounds of war:

"Did they beat the drum slowly, did they play the pipes lowly?/ Did the rifles fire o'er you as they lowered you down?"

Mr. Bogle ended, as always, with his take on "Waltzing Matilda," which he still sees not as a protest song but as a statement of facts and the feelings they engender.

When called back for an encore, he sang "Hallowed Ground," which he wrote this year after revisiting the graves on the French battlefield.

Addressing the fallen soldiers and the cyclical nature of conflict, he concluded by singing:

Oh, boys, how I'd like to tell you everything has changed

But that would be a lie

All in all, this world is much the same

Old men still talk and argue while young men still fight and die

And I still don't know why.