The self-described "cowgirl chorus" singing the harmonies to Rodney Crowell's rendition of "Even Cowgirls Get the Blues" Tuesday night at the Birchmere consisted of Emmylou Harris, Nanci Griffith, Patty Griffin and Julie Miller: an A-plus list of singers closing out an A-plus night of music.

The whole evening had the loose feel of old friends getting together to trade songs, and in one way that's what the concert was. But it was also a tribute to the emcee and headliner, Harris, who was being honored by the Vietnam Veterans of America Foundation for her work with land-mine victims worldwide.

Harris, who began her singing career in Washington clubs before becoming a country music star nearly three decades ago, received the foundation's Patrick J. Leahy Humanitarian Award in between sets of music from some of Harris's longtime musical compadres. Created in 1998, the annual award is named after the Democratic senator from Vermont (who was on hand to make the presentation) for his work on such issues as the removal of land mines.

On the bill, along with Crowell and the "cowgirls," were Steve Earle, Guy Clark, John Prine, Jamie O'Hara and Miller's husband, Buddy Miller, a stunning lineup of country-folk-rock talent. Before each took the stage for a too-brief two-song appearance, Harris would make a gracious introduction before retiring to a comfy-looking armchair onstage.

Before the music began, foundation President Bobby Muller praised Leahy, then Harris, explaining that "Emmy has conceived all this, and has led this musical parade." A short film then explained Harris's rise to activism, showing the extent to which land mines are still buried in war-ravaged countries around the world, and recounting Harris's work organizing the "Concerts for a Landmine Free World" series and helping support a weaving center in Cambodia for female victims of land mines.

Harris and the Millers next took the stage to perform "Bright Morning Stars," a meditative traditional song that set the tone for the night. Afterward, Harris -- looking radiant and gorgeous in a black gown -- said: "They told me that this was my night and asked me what I wanted. I told them I just wanted my friends to come sing for me." As the speakers briefly crackled, she grew alarmed: "I think we just lost sound! Oh, God, I'm nervous enough!"

Sound quickly repaired, Buddy and Julie Miller took the spotlight. "When I heard that she was recording one of my songs, I knew I could die happy," said Julie Miller before the duo launched into "All My Tears." (Earle later remarked modestly, "Emmy has recorded two of my songs, and that is my re{acute}sume{acute}.")

Harris noted the absence of Washington's own Mary Chapin Carpenter, who was on the bill but couldn't make it because of a bad back (but who sent flowers that were in a vase beside Harris's armchair). Then she talked about her own time in Washington.

"I know this isn't technically my home town," she said, "but so much of what I learned about music I learned right here." The 55-year-old Harris went to middle school and high school in Woodbridge, then returned to Washington in the early '70s, when she performed in places like Clyde's and the Childe Harold. ("They have a sandwich named after me there," she noted with a laugh.)

When everyone else had had a turn, Harris returned front and center, joined by her old friends from the Washington band the Seldom Scene, John Starling and Mike Auldridge, to perform "Satan's Jeweled Crown." Then the evening ended all too soon with Crowell's "Even Cowgirls Get the Blues," a conclusion you wouldn't reach by looking at Harris's glowing face.

Emmylou Harris performs at Tuesday night's Birchmere concert, where she was honored by a veterans group for her work with land-mine victims. Below, Harris gets a hug from Patty Griffin, one of the singers who came to honor her.