The bad news was that headliner Ralph Stanley, the Godfather of bluegrass, had been stranded by ice storms in the US. The good news was that we therefore got a double dose of Gillian Welch and her musical partner David Rawlings, who rose to the occasion with a dazzling exhibition of bluegrass, gospel and hillbilly mountain music.
Welch's recordings are characterised by their minimalist tone and emotional austerity, with last year's Time (The Revelator) plumbing new depths of morbidity. But onstage, although the music was often stark and the lyrics couched in the forbidding language of the Old Testament, the duo's vocal and instrumental interplay was wondrous to behold. Rawlings's high harmonies made a perfect fit with Welch's keening tone, and the live environment lent the performance a thrilling improvisatory edge, with the voices shifting and weaving with precision over an insistent rhythmic pulse.
In Elvis Presley Blues, Welch's meditation on the life and mythology of the King, the voices shimmered eerily over Rawlings's crystalline guitar picking. When I Pass Through the Pearly Gates was negotiated with pinpoint accuracy at hectic pace, while Dear Someone glowed luminously in slow-waltz time, punctuated with wonderfully unexpected minor-key twists. Throughout, Rawlings's flights of invention on lead guitar propelled the music forwards, never allowing it to lapse into mundane strumming.
There was room for a little wry humour. "You got enough room on your side of the stage?" Welch asked Rawlings, since the pair were marooned on the huge Barbican platform with only a couple of guitars, a banjo and a little box containing set lists and capos. After the plaintive sob-fest of Orphan Girl, Rawlings's promise to play "something else sort of pitiful and minor" leavened the mood of primitive suffering. But part of the duo's achievement is to have dragged this old-time music into the 21st century, and a song called We're the Outlaws Now was a piercing acknowledgment that large parts of the world think it is the Americans who are wearing the black hats.
They were joined for a few songs by Buddy Miller, hitting an especially fertile groove in Townes Van Zandt's White Freightliner before Miller rushed off to play an electric set with his band in the foyer. The bluegrass-fanciers drifted over to watch, and they caught Welch and Rawlings joining Miller for gutbucket renderings of Bob Dylan's Wallflower and Chuck Berry's Nadine. Rawlings was blasting out electric licks like Eddie van Halen, with a grin as wide as the Grand Canyon. Ralph Stanley doesn't know what he missed.