WHEN BILLY BRAGG and Wilco’s Mermaid Avenue appeared in 1997, it signified that, despite his world reputation, the world had a lot to learn about Woody Guthrie. There was a vast collection of songs, words without tunes, written between about 1939 and 1955, that Guthrie, from his hospital bed, had first offered to Bob Dylan in the early nineteen sixties. Starting in 1996, twenty-nine years after Guthrie’s death, first Bragg and then Wilco’s Jeff Tweedy and Jay Bennett began to sift through the pages, looking for the songs that spoke to them, that needed to be heard, that were just too good to leave to the archives.

But the project — here carried through across work left off that first album, Mermaid Avenue Vol. II, released in 2000, and a Vol. III, collecting 18 tracks not heard before — also marked a verge in the careers of Bragg and Wilco. Before confronting Guthrie’s legacy, their work, filled as it was with shining moments, had felt cramped, hesitant, the performers often seeming to fall short of the ambitions of their own songs. For that matter, they were dour, unsmiling. It was impossible to imagine them getting drunk, at least for fun. Now, coming across “Way Down Yonder in a Minor Key,” “Walt Whitman’s Niece,” “Hot Rod Hotel,” “When the Roses Bloom Again,” “California Stars,” “Give Me a Nail,” “Satisfied Now,” and the other half-songs they decided to try to play — to rescue, to bring to life, to complete, to change, to test themselves against — the old limits within which they’d comfortably made mostly comfortable music no longer served. The Guthrie songs that called out to them demanded that they step into clothes they’d never worn, go places they’d never been, and craft melodies more open, more evocative, than any they’d needed before. Guthrie’s songs stripped off their blinders and broke their hobbles.

As a set of lyrics, “Give Me a Nail,” from Mermaid Avenue Vol. III, bets that if it can make you believe its smallest promises — “Give me a nail, and I’ll nail it . . . Give me a row, and I’ll hoe it” — you’ll believe its last line: “Give me a world, and I’ll win it.” Bragg and Wilco kick off with a rousing, bashing fanfare, and within seconds you just want to play the song’s game, making up your own lines even as you follow from “Give me a bugle, and I’ll toot it” to “Give me a gun, and I’ll shoot it.” It sounds like a throwaway track on the seventh Byrds album — the throwaway that brings you back to the record when you’ve gotten tired of the masterpieces. Why not give this little a ditty a Top 40 arrangement? Who knows, this might be a single!

You can imagine even the musicians forgetting that, on paper, this song is of a piece with the Guthrie agit-prop or self-righteous chest-pounding numbers they’ve also tried and failed to turn into convincing music, maybe even to believe themselves: such automatic screeds as “My 30,000” or “All You Fascists,” or “Union Prayer.” So often, in Guthrie’s this-machine-kills-fascists numbers, flights of craft and inspiration are dragged down by the freight they’re forced to carry: the weighed and measured details of saying the politically proper thing in the politically proper way. In the ...