On A Small Source of Comfort, the 31st studio album by Canadian singer-songwriter Bruce Cockburn, his agile guitar steps forward in a mostly acoustic album.

Cockburn, who comes to the Keswick Theatre on Friday, offers songs that are inventive, rootsy, dark, and joyful. Add violin goddess Jenny Scheinman, who shines on the CD's five sparkling instrumentals and will perform with him at the Keswick.

It feels much like Dancing in the Lion's Jaws (1979) and Humans (1981), in which Cockburn's songs - cosmic, emotional, yet surely crafted - alongside his throaty tenor and poetry, earned him an international following.

"It was intentional," says Cockburn, 65, speaking from San Francisco. "It reminds me of my '70s albums, very folky. . . . And the instrumental pieces add to that. Jenny basically learned them in the studio."

Scheinman, speaking from Petrolia, Calif., says much of the album "incubated as we played as a duo, which we did a lot in Brooklyn. What's so attractive about his music is, a lot of his songs are these perfect pop structures - but they're also so big, so cosmic and open, and he invited me, gave me freedom to explore."

Comfort is a quiet album, seldom raising its voice. Two of its loveliest songs, "Driving Away" and "Boundless," were cowritten with accomplished songstress Annabelle Chvostek. But "a lot of these songs," Cockburn says, "come from the same place as 'Rocket Launcher.' "

That's "If I Had a Rocket Launcher," the famous - or to some minds, infamous - track on Cockburn's 1984 album, Stealing Fire, in which the speaker, furious at government persecution in South America, cries

when I talk with the survivors of things too sickening to relate

If I had a rocket launcher . . . I would retaliate

 Song and album signaled a turn for Cockburn, to an insistent, committed political stance that spoke out against oppression. That stance - along with Cockburn's oceanic, pervading spirituality - is deeply embedded in Small Source of Comfort, as in the humorous "Call Me Rose," in which the soul of Richard Nixon gets a chance to redeem itself - by coming back as a poor welfare mother:

I'm back here learning what it is to be poor

to have no power but the strength to endure

I'll perform my penance well

maybe the memoir will sell

 It's in a passing line from "Five Fifty-One," one of several road songs on the album. The speaker finds the smell of dawn "a small source of comfort":

out on the sidewalk there was diesel on the breeze

they're always getting away with something when they think there's no one there to see

 And it rises to a crescendo in "Each One Lost." Cockburn explains that en route from Ottawa to Kandahar Airfield in Afghanistan, he spent a few hours at a NATO staging base in Dubai: "We were waiting to board our plane when a C-130 landed with the bodies of two Canadian soldiers who'd been killed that day, and there was a ramp ceremony, of which we became a part, to honor the risk and sacrifice of the two men."

Some would have us bow

in bondage to their dreams

of little gods who lay down laws to live by

but all these inventions

arise from fear of love

and openhearted tolerance and trust

Well screw the rule of law

we want the rule of love

enough to fight and die to keep it coming

if that sounds like confusion

brother think again

we know exactly what we chose

These uncompromising lyrics are sung against a sweet backing reminiscent of a hymn.

"It works in several directions," he says. "Those soldiers were on the front end of a struggle against fascist fundamentalists. But the same war is going on in America and Europe, against those who would have us all live by a single set of rules, theirs, under pain of death."

What happened to radicalize a singer who once kept to love and matters of the spirit? "I saw the Third World and saw what was happening there," Cockburn says. "I once thought art and politics shouldn't mix, but that's transparently false - think of [John McCrae's poem] 'Flanders Fields.' The power of Guernica lies in Picasso's outrage. When art mixes with the political, it becomes powerful for change, becomes threatening to regimes."

A Small Source of Comfort ends with a gift - the tune "Gifts," with which Cockburn closed concerts back in the day, but never put on a recording until now. Why now?

"I told Bernie Finkelstein, my manager at the time, 'I'm saving it for my last album,' " Cockburn says. "When he heard it was on Small Comfort, he asked me, "Anything I should know?" I said, 'It's just in case. There may be more albums, but who knows?' "

Free Cockburn

To download a free Bruce Cockburn song, go to violinist Jenny Scheinman's website, www.jennyscheinman.com, for the unreleased track "The Littlest Prisoner."


Contact John Timpane at 215-854-4406, jt@phillynews.com, or twitter.com/jtimpane.