If Jimmie Dale Gilmore and Butch Hancock are two of the best singer-songwriters in America today, you might ask, why aren't these old friends from Lubbock, Tex., better known? Well, it might have something to do with the fact that their legendary 1972 album as the Flatlanders was released only this year, that their superb Australian live album still hasn't been released here and that they've only appeared together twice in a major market like ours. Their show at the Birchmere Tuesday night, though, was so impressive that their eventual recognition seems inevitable.

When Gilmore stood tall and skinny in his black cowboy shirt and sang "Tonight I Think I'm Going to Go Downtown," his quivering twang had the open-hearted purity of his namesake Jimmie Rodgers. When the unshaven, square-jawed Hancock leaned over in his eye-smarting flower shirt and punctuated his florid sprawl of metaphors and imagery on "Two Roads" with harmonica blasts, he sounded like Bob Dylan singing from the cab of a West Texas pickup truck. When they sang duet vocals on Gilmore's "Dallas" and Hancock's "If You Were a Bluebird," they sounded like a reunion of Lubbock ghosts, from Buddy Holly to Waylon Jennings.

Gilmore and Hancock were part of the "Exiles From Main Street" songwriters showcase, hosted by Nashville tunesmiths Tom Russell and Greg Trooper and backed by guitarist Andrew Hardin and fiddler-accordionist Fats Kaplan. The redheaded country blues singer Katy Moffatt, who has the talent to survive the inevitable Bonnie Raitt comparisons, and the L.A. country-rock pioneer Steve Young were among the special guests. Russell, Trooper, Moffatt and Young are all fine singer-songwriters who turned in solid, enjoyable four-song sets.

Only Dave Alvin, however, could stand up to the example set by Gilmore and Hancock. Wearing a purple cowboy shirt with a string tie, Alvin slowed down "Fourth of July," which he had recorded with X, until the confession took on new tragic dimensions. He framed "Long White Cadillac," which he had recorded with the Blasters, with a biting blues lament, "Nobody's Fault but Mine." Alvin has a limited voice, but he has never used it more effectively than he did Tuesday night.

Alvin headlines at the 9:30 club next Monday. Gilmore and Hancock headline at the Wolf Trap Barns March 2.