In the 21st century Kenny & Amanda Smith fall very much into bluegrass' mainstream, even though their smooth vocals and mid-tempo songs would have surprised the foundational acts of the late 1940s and early 1950s. Still, a fairly straight line connects the couple with such later bands as the Country Gentlemen and the Seldom Scene. Groups like these helped make the genre more palatable, which is to say less rural, to potential fans outside the Southern culture of country music. Change being inevitable, much of bluegrass is not what it was. Nothing necessarily wrong with that, but if you grew up with it, you can't help lamenting the declining prominence of deep bluegrass even as more modern acts infuse the music with welcome creative energy.

Amanda Smith, whose voice can be accurately characterized as crystalline, is among the most praised vocalists on the current scene. Her husband Kenny is a superb flat-picking guitarist. On Unbound they're joined by a small but impeccable line-up of bluegrass players. As if that weren't enough, the CD is nearly 50 minutes long, in other words about 15 to 20 minutes more than the average bluegrass disc.

The standout is Gordon Lightfoot's "Wherefore & Why," which started life as the opening number on his 1968 album Did She Mention My Name? Lightfoot's 1960s/'70s output has stood up remarkably against the onslaught of two subsequent generations of lesser singer-songwriters. John Prine and Bob Dylan have voiced their full-throated appreciation, and I need to say no more, only that the Smiths ably affirm what a terrific song "Wherefore" has always been.

As much as there is to like here, however, I wish that the material were more consistently appealing. The Smiths are drawn to a country-pop sound. Some of it has the bland character of what you hear -- that is, if you're still listening to it -- on current country radio, except with acoustic arrangements. There's little of the spirit that defined, and defines, traditional bluegrass, and one misses the Appalachia-inflected melodies, not to mention the compelling narratives associated with folk and related music. The Smiths are hardly alone in eschewing an earlier model of bluegrass songwriting (all of the songs are from other writers). Still, I can't imagine what the attraction of piffle like "Tea Party" (not about the hard-right political movement) can have been to the Smiths. It's just plain, no other word comes to mind, dopey. Artists who work at their level of musicianship ought to be giving their audience, and themselves, something better than this.

And then there's the Larry Stephenson Band, carriers of traditional bluegrass' flame. Mandolin player and vocalist Stephenson learned from the masters, by whom I mean the Osborne Brothers, in whose group he served his apprenticeship. Even now, as Stephenson closes in on three decades as leader of his own outfit, one can hear echoes of Bobby Osborne's unforgettable tenor.

Last time around, Stephenson dealt in gospel. I reviewed his powerful Pull Your Savior In here on 29 November 2014. This time, on Weep Little Willow, only "Best Laid Plans" (by Rick Lang and Troy Engle) has a religious theme, though not a heavy-handed one; one can as easily hear it as a statement on the vagaries of fate. One happily notes credits to the revered likes of Bill Monroe ("Kentucky Waltz," of which no bluegrass lover could ever tire), Mac Wiseman ("Free Me from This Old Chain Gang"), and Alton Delmore ("Midnight Train"). Before one has heard them, one is confident they will be done justice, and one is not disappointed. The heartrending "Let Those Brown Eyes Smile at Me," which Stephenson may have been born to sing, puts all of us who love sad old country heart songs in his debt.

The one surprise is the opening song, which I hadn't heard (or thought about) since it was a British Invasion hit half a century ago: Chad & Jeremy's folk-pop "Yesterday's Gone." It proves to be an inspired choice; one would almost think it was intended to be bluegrass all along. Of course a lot of it owes to the Stephenson Band's sparkling harmonies, in evidence throughout the disc and just one of its many lovable qualities.