Few things last this long — Mary Chapin Carpenter and Shawn Colvin have known each other for about half of their lives. Theirs is, as Carpenter puts it, “a singing friendship.” And as we discovered on Friday night at the Charleston Music Hall, their abiding bond is our musical reward.

Carpenter, whose vocals are a sweet, aromatic pipe smoke made audible, and Colvin, whose lyricism can be as sharp as the leading edge of single malt scotch, not only complement each other musically, they draw one another out on stage. Cheerful co-conspirators, they shine in their own buddy movie.

“We are,” Carpenter told the audience, “like the Tina Fey and Amy Poehler of folk music.”

Colvin took a beat to consider this. “I think of us as the Smothers Brothers.” She scanned the crowd for their nodding recognition of the ’60s era folk-singing comedy duo. “And I’m Tommy,” Carpenter added, referencing the perennially dim-witted half of that partnership.

The audience laughed, but not because they bought the notion that either of these two artists are less than stellar. Fresh from a tour stop at Nashville’s legendary Ryman Auditorium, Carpenter and Colvin lay claim to a shelf full of Grammy awards, numerous chart-topping hits, and a legacy of musical achievement with more than a dozen album releases each. What they bring to their performances are the real benefit of all that shared experience: the ability to reflect meaningfully on larger themes.

“The greatest songs not only move you,” said Colvin, “they tell a story as well.”

And so their show told those stories through original tunes and cover songs chosen, Colvin said, because they’d been written “by people we revere.”

The evening kicked off with the Don Henley and Bruce Hornsby penned “The End Of The Innocence.” The crowd let out a whoop when Carpenter and Colvin sang “They’re beating plowshares into swords / For this tired old man that we elected king.” Donovan’s shimmering “Catch the Wind” followed. Songs by Paul Simon, Emmylou Harris, and Steve Earle added their lyrical perspectives, rounded out by a gorgeous version of Lennon and McCartney’s “I’ll Be Back.”

Colvin awarded her song “Sunny Came Home” pride of place, calling it “my best break-up song.” Even so, her composition “These Four Walls” stood out; it contains unsparing lyrics and more beautiful for it.

Carpenter gave a haunting rendering of her song “This Shirt” about which the author said, “It’s all true!” which only made the song more poignant. She scored again with “Our Man, Walter Cronkite” a nostalgic glance and forward looking stare combined in one emotional punch.

Song after song, the duo reflected on the place of love and loss in our lives; on looking back not to escape into the past but to understand where we once were and re-imagine how we might yet be in this moment.

It was not entirely surprising when Carpenter asked Colvin, “What would you tell your 16-year-old self?”

“I was very happy at 16.” Colvin shrugged. “It didn’t last, of course.”

Carpenter had a list of answers to the question, among which was this: “Failure is your greatest teacher. Follow failure.”

Having taken a moment to think about her own responses, Colvin offered, “I would say, you’re never alone in anything you do or try. And that this too shall pass.”

Perhaps, as Colvin asserted, all things — good or bad — shall pass. And perhaps that is why we treasure those singular things like this duo’s decades-long friendship that, despite the odds, still abides.