The bluegrass revival gravy train rolled into Wolf Trap on Wednesday night for a three-hour jamboree of traditional Appalachian and old-time country music.

Like an acoustic version of its punk-metal counterpart, Ozzfest, the Great High Mountain Tour boasts dozens of musicians, including a legend (Ralph Stanley), a big-name draw (Alison Krauss and Union Station) and young upstarts (15-year-old Cody Hull and his precocious mandolin-playing sister Sierra, a true 13-going-on-30-year-old).

Comparisons to Ozzfest end there, however. None of this music threatened to rupture eardrums, and picnicking nosh pits replaced mosh pits as the settings of the most frantic activity.

The current bluegrass boom and traditional American music renaissance is due, of course, to the continued success of soundtracks to "O Brother, Where Art Thou?" and "Cold Mountain," and this concert was heavy on songs from both.

From the "Cold Mountain" CD, the always wonderful Krauss and Dan Tyminski performed the Oscar-nominated, Sting-penned "You Will Be My Ain True Love," while Tim Eriksen, Riley Baugus and Dirk Powell sang "The Cuckoo" as well as a harrowing version of "Wayfaring Stranger."

From "O Brother," Union Station delivered "Man of Constant Sorrow," while Krauss joined with Ollabelle's Fiona McBain and Amy Helm for a lovely a cappella take of "Didn't Leave Nobody but the Baby."

But the 77-year-old Stanley, who received one of those lifetime-achievement standing ovations when he walked onstage, was the evening's main attraction. Introduced by Krauss, who called his voice the "meanest, lonesomest and saddest" in bluegrass, Stanley looked every bit the icon he has become. Playing with the Nashville Bluegrass Band, he did a little banjo picking of his own on "Girl From the Greenbriar Shore," but it was a truly frightening rendition of "O Death" that held the crowd spellbound. His voice cut through the clear night air; severe, despairing, beautiful and immortal all at once.

-- Joe Heim