On their fourth album, the Nashville-based Grascals welcome two new members, award-winning banjo player Kristin Scott Benson and fiddler Jeremy Abshire, while consolidating their reputation as one of the more impressive of the younger bluegrass bands. If the sound is slick and modern, it encompasses enough traditional references to make clear theirs is no attempt to expand or defy the broadly accepted definition of bluegrass.

The Famous Lefty Flynn's also highlights the band's overall good taste in songs, not least the title tune, a prisoner's tale with a neat twist, written by Grascal guitarist Jamie Johnson with Morry Trent. The Grascals' treatment informs me that Steve Earle's "My Old Friend the Blues" is better than the tossed-off exercise I'd remembered (barely) from the Earle original. Another highlight is "Satan & Grandma," written by Craig Monday and Chris Wallin, the most creatively conceived and appealing gospel number I've heard in a while.

Less happily, the opening cut, the Tommy Boyce/Bobby Hart "Last Train to Clarksville," a 1966 hit for the Monkees, is a song of no distinction, notwithstanding the novelty of an energetic, accomplished bluegrass treatment. I was not surprised to read recently that it is the chosen single from the album, which no doubt was the point all along.

More happily, there's the one pure-country cut, the often-covered "I'm Blue, I'm Lonesome," composed in hillbilly heaven by Bill Monroe and Hank Williams -- unfortunately, their sole songwriting collaboration. This version boasts steel guitar, drums and Hank Williams Jr. If a fairly standard reading, it is done effectively.