When he died of cancer on August 7, 2009, Mike Seeger left heartbroken those whom his music had touched. Like most who knew that music, I would never meet him personally. I did see him once in concert, albeit as a solo act apart from his other gig, which was as a member of the New Lost City Ramblers. The NLCR, which Seeger co-founded in 1958, wielded an immense impact on the emerging folk revival. Over the decades, even after folk had passed out of popular fashion, they as a group and Seeger as an individual were influencing a wide range of American musicians of all stripes. Toward the end of his life, Seeger was recording with the likes of Ralph Stanley, Ry Cooder, Alison Krauss and Robert Plant. Meantime, in his best-selling memoir, Bob Dylan was giving voice to unbridled admiration. Culture critic Greil Marcus, caustic about much and many, pronounced Seeger a jewel in the American crown.

Most immediately, the NLCR provided an alternate route for citybillies, away from the Kingston Trio folk-pop and toward authentically performed old-time Southern stringband music, particularly (albeit not exclusively) the kind captured on 78s in the 1920s. Even after those original 78s that so stirred Seeger and associates John Cohen, Tom Paley and Tracy Schwarz (Paley's replacement) have been widely reissued in the decades since, the NLCR's recordings -- the last of them was issued in 1997 -- still have the power to move and thrill. Their career is the subject of an acclaimed history, Ray Allen's Gone to the Country: The New Lost City Ramblers & the Folk Revival (University of Illinois Press, 2010). Country music scholar Bill C. Malone's biography of Seeger, Music from the True Vine, will appear in October.

A multi-instrumentalist, Seeger also recorded a number of albums on his own. In his last two decades or so, he seemed to be trying to make the music even older than it already was, with arrangements, tunings and vocals imagined from lost, unrecoverable American sounds. No direct reproduction of any of this remains, only printed accounts by 18th- and 19th-century chroniclers who heard the music, wrote down melodies and lyrics, and tried to describe what they had heard. I refer those curious about what Seeger's experiments in musical ageing sounded like to Solo: Oldtime Country Music (Rounder, 1991) and True Vine (Smithsonian Folkways, 2003). Still reaching greatness when he left us, he was no less than an unceasing marvel. All of my adult life, the release of a new Mike Seeger record was reason to rejoice.

On the occasion of his passing, I assumed his voice was forever silenced. What a happy surprise is Fly Down Little Bird, appearing as if out of nowhere -- 14 pure traditional American songs in duets with his sister Peggy, herself a notable folk singer albeit more known for her political songwriting. (The comparably left-centric Pete is an older half-brother.) Mike and Peggy sang together as children and on all through their lives; this is their third, one presumes last, album together. We all owe Peggy a debt for making possible this lovely, inevitably bittersweet final bow.

The singing is warm and unadorned, played straightforwardly on elemental downhome instruments: guitar, banjo, fiddle, harmonica, piano and variants. The songs, familiar and not-so-familiar, range from favorites such as "My Home's Across the Blue Ridge Mountains" and "Little Birdie" to obscurities like "Fod!" and "Blood-Stained Banders." I am cheered to hear the too seldom revisited "Dodger Song," a protest piece of mordant humor dating to the Populist era of the late 19th century. The pioneering Popular Front folk group Almanac Singers -- one of whose members was Pete Seeger (Woody Guthrie was another) -- cut it 70 years ago. Surely, that's an unbroken circle of some kind.

If this is Mike Seeger's last word, it is a true one. But then, he never sang another.