A dazzling turn from folk icon

British folk guitarist-singer Bert Jansch’s renown is often defined by the influence he’s had. His praises have been sung so famously by figures from Jimmy Page and Neil Young to young acolytes such as Beth Orton and Devendra Banhart that it can obscure what made him an icon in the first place. No such problem at the Troubadour on Friday, where he gave a dazzlingly engaging solo performance demonstrating just why those musicians follow this leader.

The 63-year-old Glaswegian performed with the grace and fire that have marked his 40-plus year career as both a solo act and a member of the groundbreaking folk-jazz group Pentangle. His guitar mastery usually gets most of the attention, and there was no lack of that Friday. From the quasi-Baroque of “My Donald” to the Piedmont-style rag “Trouble in Mind,” he showed that the way he’s processed blues into British Isles folk music with touches of classical and jazz stands as a nonpareil hybrid. And his version of the traditional “Blackwater Side” (a template for Page’s “Black Mountain Side”) remains the epitome of economical virtuosity.

But his underappreciated singing stood out equally at the Troubadour. His phlegmatic but acidic voice bore bite as much in songs from centuries back (the bitter ballad “Katy Cruel”) as ones of this moment (“Poison,” his pointed 1969-but-still-relevant sketch of environmental and spiritual ruin), stark narratives of misfortune and struggle -- and the resolute defiance that breeds.

The generations-spanning audience also embraced a winsome opening set by Meg Baird, another young Jansch devotee who as a member of the Pennsylvania band Espers performed on his 2006 album, “The Black Swan.”

It was Jansch’s night, though, a show that reminded that when he emerged in the mid-’60s, he sounded like no one before, and that after all these years and all those would-be imitators, no one sounds like him still. That’s a definition of a true artist.