Today, bluegrass, which thrives decades after its creation in the latter 1940s, can be broken down into three schools, each with its own specific classrooms: traditionalist, modernist and one that splits the difference. Russell Moore and IIIrd Tyme Out -- Prime Tyme is the well-regarded band's 16th album -- are in the, er, third, though you might also judge them something like a 21st-century Flatt & Scruggs.

In the fashion of Southern bluegrassers, four of the band's five members use the liner notes to affirm that either God or "my Lord and Savior" is their No. 1 inspiration. I always take this as a mark of authenticity. When the band consists of unabashed evangelicals who don't hesitate to mention the Lord whenever the opportunity presents itself, you know you're dealing with the real deal, as opposed, say, to a bunch of banjo-brandishing agnostic Yankee poseurs. These guys do not disappoint, really, on any level. They're pros, they play marvelously, and they know good songs when they hear them. On this outing, the liner testimonial notwithstanding, the songs are secular themed.

The material derives from tradition ("Carroll County Blues"), from vintage country (the Delmore Brothers' "Gonna Lay Down My Old Guitar," Hank Garland's "Sugarfoot Rag") and from accomplished modern bluegrass writers with old-soul sensibilities (David Norris's lovely "Dusty" is one memorable example). Rather remarkably, there is an openly expressed sympathy for the downtrodden. One wishes certain of our elected officials -- as often as not representing Southern states from which bluegrass springs -- shared it. Mark Brinkman's "Hooverville" is a song Woody Guthrie could have written. So is most of Ronnie Bowman and Michael Garris's "What's the World Coming To?," with its condemnation of "money rollin' in for politicians and Wall Streeters." If, as some have suggested, the political zeitgeist is changing, this bluegrass album is one more item of evidence.

Another unexpected development, albeit not a political one, is the appearance of Willis Alan Ramsey's "Goodbye Old Missoula." Now there's a song one couldn't anticipate on a bluegrass record. (The still-definitive version, by the way, can be heard on Jimmie Dale Gilmore's 2000 Rounder release One Endless Night.) In the most literal sense, it's about a road musician who wakes up hung over, depressed about his failure the previous night to score with a local woman who "did not have eyes for me." Something about Ramsey's way of telling the story, though, elevates this banal circumstance to something like cosmic mystery. It's a terrific song, but you have to be pretty damn good to sing it convincingly enough to communicate its core strangeness. The band manages to do that, improbably, with bluegrass instruments and harmonies.