To paraphrase what Dr. Johnson famously said of London and life, when you're tired of Doyle Lawson you're tired of bluegrass. Most artists who succeed in bluegrass stay with it for decades, and Lawson is no exception. In fact, his career spans most of the history of the genre.

An evolutionary development at varying distances from the oldtime stringband tradition, bluegrass as a distinct style of music is usually dated to the late 1940s. Lawson, who started playing mandolin when he was 11 (banjo and guitar later), joined Jimmy Martin's Sunny Mountain Boys in 1963, then hitched up with such influential groups as J.D. Crowe's Kentucky Mountain Boys (subsequently renamed the New South) and the Country Gentlemen. In 1979 he ventured in a solo direction to fashion a specifically Lawson sound in collaboration with his own band, which he called Quicksilver.

Since then Quicksilver has hosted a shifting line-up over the four decades of its existence, often talented young pickers who have become admired figures in themselves (Lou Reid, Terry Baucom, Russell Moore, Scott Vestal, Jim Mills, Steve Gulley). Not counting a handful of compilation discs, Live in Prague is the 42nd album adorned with Lawson's name.

From the first, in 1977, Lawson (inducted into the International Bluegrass Hall of Fame in 2012) seemed to emerge fully formed. He had a style he wanted, and he set out to secure the musicians who could carry it into the world. His band is famous for its distinctive harmonies and for the mid-century character of the songs, shaped by Lawson's fascination with Grand Ole Opry radio broadcasts heard in his early years. (No one has ever characterized Lawson's approach as "mountain bluegrass.") He also sprinkles his repertoire with hymns and gospel tunes, sometimes whole albums' worth.

Which is a way of leading up to this point: Lawson knows exactly what he wants to do and how to go about it. When you pick up a Lawson recording, you know what you're getting. To the critic there's an additional consideration: the albums are reviewer-proof. If you want to knock them, you need to hold an irrational prejudice against Lawson and perhaps bluegrass itself, in which case you should have just let them be.

As the title tells you, Live in Prague affirms, in case you might doubt it, that there are enthusiastic fans in the Czech Republic. Beyond that, it's a special pleasure to hear Lawson and Quicksilver's gorgeous reading of the stirring hymn "On the Sea of Life." All that needs to be said to the potential consumer is that this is their latest release. Where praise is concerned, that ought to be sufficient to cover the bases.

Last time I wrote about an Audie Blaylock & Redline CD, not recently, I had no complaint to register about Blaylock's singing and his band's playing, but I did express unhappiness with the material, which I deemed unworthy of a group with this one's manifest virtues. No such bellyaching this time. The material is strong, and everything works to conjure up powerful Appalachian music. "Prodigal Son" is traditional, as in traditional folk song, and arranged accordingly. Ralph Stanley and Bill Grant's chilling "Medicine Springs" could easily pass for a 19th-century murder ballad.

Otherwise, "traditional" is as in traditional bluegrass. In an interview last year with Bluegrass Today, Blaylock says, "We play traditional bluegrass music, but we don't play the same songs as the founders. We want it to sound new and fresh, but we try to play it in the same spirit as the guys who were doing it in the '50s." For Blaylock, another veteran of the genre -- his long involvement is the subject of two witty photographs on Originalist's front and back covers -- the founders aren't guys known solely from old records. Like Lawson's, Blaylock's career was launched under Jimmy Martin's tutorship.

As a devotee of hardcore bluegrass nearly all of my life, I am always thrilled to find it's still around and in good hands. These, let us be clear, are the best of hands.