In recent years, as old-time music has undergone an unlikely and unanticipated revival, some artists -- especially younger ones -- have reinvented the music, sometimes to the point of reducing "old time" more to influence than definition. That's all right if the result proves to be something worthwhile; otherwise, it's just fusion for pointless adventure's sake.

I remain partial, myself, to old-time string bands that hold to the authentic stuff. By "authentic" I do not mean rote and repetitive. There's no end of reissued CDs to inform us how the music sounded in its natural setting when early record companies began collecting it in the 1920s and marketing it commercially, bringing into the world the genre that, much altered, would eventually be called "country." If I want to hear how Gid Tanner & the Skillet Lickers performed "Soldier's Joy," I listen to them, not to some latter-day band reproducing their sound more or less note for note. I also look for a repertoire that encompasses more than the songs and tunes -- only a sampling of what was out there -- that happened to attract the attention of A&R men seven or eight decades ago.

The Buck Mountain Band and Harmon's Peak manage all of this and more. These are two of the most thrilling old-time stringband albums you'll hear this year. The music is lively, fresh-sounding, beautifully played and imaginatively constructed, with strong, well-chosen material. To accomplish what these two bands have done, you need, first, to lay claim to more than a passing knowledge of American folk music and, second, to be technically proficient enough to play it in a way that both honors the tradition and opens up interesting personal interpretations of it.

The five-piece Buck Mountain Band hails, spiritually as much as literally, from Grayson County, Va., and reflects that musically rich area's love of melodic fiddle tunes. Its most famous member is Larry McPeak, of the celebrated McPeak Brothers bluegrass band -- though, let us be clear, BMB is not a bluegrass outfit by any definition. Guitarist McPeak contributes one of the two songs among the otherwise-instrumental cuts (19 total), the very sad, sadly true story of a bloody Civil War-era battle that should never have been fought ("Dry Run Creek").

Overwhelmingly traditional in origin -- though there is a terrific, unWestern-swing arrangement of the Bob Wills standard "Silver Bells" -- the melodies are culled from an array of rural sources, not all of them Southeastern, but BMB's treatment affords them that consistent point of reference. Unlike too many mostly instrumental albums, Moon Behind the Hill is confident and assertive in ways that will not allow it to pass as background music. The playing is too distinctive, and the tunes too beguiling, to let that happen.

Harmon's Peak, out of California, offers up more antique resonance, less specifically Southern. Folk string bands, after all, abounded everywhere, nearly as omnipresent as village brass ensembles, in historical North America, even if today they are almost invariably associated with Appalachia. Most of Harmon's Peak's songs and tunes were current around the Civil War period, and some had been around decades before that.

The four members pull tunes from the Old South, inevitably, but also out of the Stephen Foster ("Some Folks") and Henry Clay Work ("Year of Jubilo") songbooks, British broadsides, prairie ballads and New England dance music. They make no effort to carry the lyrics aloft on high-lonesome wings. That alone renders them something of an anomaly. But they're more than some passing curiosity in that regard, and moreover, they need be no more than themselves; their own natural voices, wholly suited to the material, suffice. This sort of album you play for the friend who knows nothing of the stringband tradition -- and for the friend who knows plenty of it. Harmon's Peak's many pleasures await anybody with ears and taste.