Years ago, a New York Times critic, writing on what appealed to him about pop music, praised what he called its "disposability." For me, the observation gave voice to what till now had been only an inchoate thought. It clarified a long-evolving disenchantment with mass-market sounds. It's my view that the things that matter are the things that last. That judgment covers a broad range of cultural phenomena, and it is a fundamental reason that folk and folk-based music, exemplifying durability, will never fade from my affections.

Traditional music performed by those (mostly rural) singers and instrumentalists who carried it in its native environment is available wherever recordings are preserved. I have more archival recordings -- some labels specialize in nothing else -- of American vernacular music than I could shake my finger at, in the unlikely event that I had the time and the inclination. Whenever I listen to it, I am seized with something like joy. And yet that's not all of it, by a long measure. I am also fascinated by what current artists, including (happily) an expanding number of younger ones, are doing to keep folk music alive and vital.

Lots of interesting things, I'm learning, in all sorts of creative interpretations. Red Tail Ring and Sarah Alden start from the same place, broadly speaking, but present the old music in notably dissimilar ways.

Red Tail Ring is a duo comprising Michael Beauchamp and Laurel Premo of Kalamazoo, Michigan. Though they don't imitate the Carters' distinctive sound, on The Heart's Swift Foot Beauchamp and Premo may turn your thoughts to the Carter Family. There's the harmony singing, of course, but more especially, the Carters loved emotionally rich, stick-in-your-head melodies, with lyrics that expressed love and sorrow at their most intense. So in many ways does RTR, which, however, brings a broader array of supporting acoustic instruments to the project than the Carters' guitars and autoharp did. RTR's songs are imbedded inside arrangements that, alongside guitar, draw on banjo, mandolin, fiddle, dobro and (yes) feet.

With a couple of exceptions, the songs are originals, invariably tuneful and nicely crafted, with lyrics that, if inflected with echoes of the older vocabulary of venerable folk song and parlor ballad, take the listener outside any particular moment or period. There is also a powerful version of the often-covered "St. James Hospital," the effect of which is to inspire hope that, as impressive as their own compositions are, Beauchamp and Premo will feature additional traditional material on their next album.

Sarah Alden, a fiddler on the New York folk scene, is both more and less traditional than RTR. Half of Fists of Violets' 10 cuts are out of authentic grassroots music -- those who know such will recognize the titles -- but the supremely extroverted Alden has re-imagined them, sometimes radically. The least of it may be the opening cut, "Dink's Song," collected by John Lomax a century ago and a 1960s revival favorite. Alden arranges it as a country song, though it is not in any sense a country song; it certainly has never been recorded by any Nashville singer I've heard. Nor does the arrangement make this profoundly sad lament "country." Still, it works.

It's nothing, though, to the next cut, a wild, rocked-up romp through the well-known fiddle tune "Ida Red," which throws Western swing (no doubt inspired by Bob Wills's recording) and Eastern European rhythms into the mix, then pushes pedal to metal. It gets your heart racing, for sure.

Later, there's a ... well ... deconstruction is the aptest phrase, probably, of "Ruby, Are You Mad at Your Man?" That one was already the subject of seminal recordings by alleged composer Cousin Emmy (who was sort of a female Grandpa Jones) and the Osborne Brothers, and Alden knows better than to compete. Better to make up her own "Ruby," and she does that sizzlingly, with the original idea of the song a mere launching pad for musical space exploration.

Even so, the rocket ship remains happily under control and on course. "Ruby" is Cousin Emmy's slight rewriting -- actually, the only nontraditional part of it may be the refrain quoted in the title -- of an enigmatic, Reconstruction-era folk song with many variants, among them "900 Miles," "500 Miles," "Old Reuben," "Train 45" and more. It's safe to say it has never been done like this.