Unplugged and unmiked, Larry Campbell and Teresa Williams moved to the lip of the stage to sing their final encore without electric assistance – naked, but not literally, as Campbell put it.

You could hear a guitar pick drop as the fans gathered in Woodlands Tavern listened intently to “Your Long Journey,” Doc Watson’s heartbreaking song about death coming to separate a couple after a lifetime together. Campbell played a gorgeous melody as he and his wife of three decades harmonized together and looked nearly as moved as the audience as they sang, “Oh my darling … oh my darling …”

This tender moment followed a ribald version of “Deep Elem Blues,” which found the audience spontaneously clapping along as Campbell and Williams sung about the town that ruined a preachin’ man for good. And that had come along after Williams, hands in the air, stomping her open-toed ankle boots, preached the musical gospel on “Keep Your Lamp Trimmed and Burning” to bring some religion to the Columbus bar on a Wednesday night.

The so-called First Couple of Americana come at it from different places even as they come at it from a shared perspective.

He is the city boy from New York who grew up seeing concerts at the Fillmore East, including Led Zeppelin opening for Iron Butterfly — “It wasn’t good for the Butterfly,” Campbell said. He’s a baritone and multi-instrumentalist (Campbell played guitar, fiddle and mandolin during the two-hour set) who logged time in Bob Dylan’s band before he and Williams hooked up with Phil Lesh and then Levon Helm and they performed “Poor Old Dirt Farmer” in memory of what they described as their musical nirvana with the former drummer for the Band.

She’s a country girl from (really) Peckerwood Point, Tenn. – “It makes Mayberry look like Atlanta,” Campbell said — who grew up picking cotton and having to avoid parties where fiddles were played because fiddles are the devil’s instrument. She’s a mezzo-soprano and guitarist who knows how to get inside an audience and evoke emotions you don’t always get from quotidian life.

On stage, Campbell and Williams banter like a married couple and sing like siblings. He calls her “luminous” and his muse; she calls him “inimitable” and professes jealousy at his formative musical experiences. Campbell spent the evening smiling in Williams’ direction; Williams spent the evening looking lovingly in Campbell’s. It was sweet, spontaneous – and obviously not a part of the show.

When Williams said she doesn’t want to know why or when Campbell wrote “Did You Love Me at All,” he replied that a muse is a complicated thing; they laughed together before singing the tear-jerker together.

Playing original songs from their two recent duo albums, it was immediately clear that Campbell-penned numbers such as “When I Stop Loving You” and “Save Me from Myself” deserved a space next to canonical American tunes such as the Rev. Gary Davis’ “Samson and Delilah” and the Louvin Brothers’ “You’re Running Wild,” all of which were played at the spellbinding concert.

The couple set the standard early, opening their show with the Carter Family’s “You’ve Got to Righten that Wrong” before moving into their own “Surrender to Love.” Historical and contemporary. Universal and personal. It was a pattern that would continue all evening long as Campbell’s fingerpicking, sawing and strumming laid down a bed for the pair’s luxurious harmonies and Williams’ occasional rhythm guitar and shakers and made one wonder why Larry Campbell & Teresa Williams are playing bars to hundreds of fans instead of playing arenas to thousands.