Had she been around a half-century earlier, Welch's simple, prairie-belle fashion sense would have made her a perfect candidate for an extra's role in The Grapes of Wrath. In her appearance as in her songs, she displays the sort of retro-functional sensibilities that have no expiration date and lack even the slightest hint of artistic pretension. Simply put, Welch lives for American roots music -- or her version of it, at least, a neo-traditional composite of folk, C&W and, especially, bluegrass.

"I like the word 'contemporary' in there. Let's not forget that you're always trying to do something new," says Welch, alluding to the fact that she tries not to let herself feel confined by genre. "The [bluegrass/roots] form has its advantages and disadvantages. There's a whole host of stuff that I don't even have to think about. Like harmonically, there are certain chords that I simply can't use. Likewise with words and lyrics -- I would never use the word 'cellular phone' in the genre I'm working in. It has no business there."

At 28, Welch has already drunk copiously from a well of ideas and styles generations deep. Her debut CD, Revival, sifts through past eras for its detail and color, and hardly ever sounds dated doing so. In her hauntingly rugged tenor, she sings of dust bowl casualties, bootleggers, women of questionable virtue and abandoned children with equal parts insight and compassion, all the while retaining the distance of an observer taking in the sights from the road. Welch deals in plainspoken verse -- few words, loads of implications -- delivered in a curious, common-folk drawl that belies her cultured upbringing.

Though she admits to it only reluctantly, Welch has always seen herself as something of an outsider. "Orphan Girl," Revival's first and best track (which was covered to tender effect by Emmylou Harris on Wrecking Ball), deals head-on with her feelings of detachment. Like any skilled storyteller, Welch makes it necessary to read between the lines to get at her secrets, funneling personal issues into fictional likenesses. In this case, it's that of a lonely little soul with "no mother, no father, no sister, no brother," who'd be happy to "share my troubles / If you go my way."

But Welch says she's also an optimist, pointing to "Acony Bell," a sweet, life-affirming tribute to her favorite mountain flower, as the song on Revival that best sums her up. "That one is probably the least cloaked -- where I can say that yes, that person's me," she admits. "And that's not a very heavy tune."

Welch's parents were a songwriting team who composed music for the Carol Burnett Show, and her childhood soundtrack featured the likes of Irving Berlin and Randy Newman. "I wasn't terribly social in high school," Welch says. "I was one of those weird combinations. If I'd had three feet, I would have had a foot in the jock camp, one in the nerd camp and one in the art camp."

An excellent student and exceptional cross-country runner, Welch spent what little free time she had learning various instruments -- piano, drums, guitar, ukulele -- and her family would often sing and play together.

"I knew a truckload of standards," recalls Welch. "I used to be able to find my mother in the shopping mall by her singing, which for a ten-year-old is a pretty embarrassing thing."

By the time she finished high school, Welch had moved from the Beatles and James Taylor to R.E.M. From there, she graduated to the punk-ethnic strains of Camper Van Beethoven, whose members were taking classes at the University of California at Santa Cruz when she enrolled there in the mid-'80s. Welch's roots music initiation came at weekly bluegrass jams in a Santa Cruz pizza joint. Her interest in mountain music sparked, Welch went about devouring the traditional recordings of the Stanley Brothers and Norman and Nancy Blake, as well as the new-grass styles of Peter Rowan and the Nashville Bluegrass Band.

It didn't take long for Welch to realize that she had found the genre closest to her heart. But it took her some time to act on that realization. She kept her love for bluegrass largely a secret while performing with a campy party band.

"I had terrible stage fright," says Welch. "I really didn't start performing in front of people until I was 20. I played with this funky band Sofa. We wore really crazy '70s clothes and did TV theme songs and Elvis tunes -- also a lot of Neil Diamond and Black Sabbath. It was so far removed from me and my writing that it never really felt like it was me up there. I never really had to take it seriously."

Following her time at UC/Santa Cruz, Welch moved east to attend the Berklee College of Music in Boston. There, with some coaxing from instructors, she slowly began to emerge from her shell. Soon, she was playing solo acoustic sets of offbeat folk and bluegrass tunes in local coffeehouses. Her last year in Boston, Welch met David Rawlings while both were members of Berklee's traditional country band. Before that, Rawlings had been playing guitar in an outfit whose musical taste ran to the Pixies. But like Welch, he was as hip to the Delmore Brothers as he was to Throwing Muses. The pair clicked as friends, eventually fell in love and then moved to Nashville together in 1992.

While the two originally went to Nashville so that Welch could concentrate on her writing, performing soon took on added importance. Rawlings began joining his mate for various open mike nights and songwriters' forums around the city. Eventually, a publishing deal with Almo Irving Music, turned into a recording contract with Almo Sounds, which resulted in Revival. The CD was produced with a skilled and sparing touch by T-Bone Burnett, who's worked with everyone from Lyle Lovett to Los Lobos to Elvis Costello, and features support from an impressive list of session players, including omnipresent studio drummer Jim Keltner and Nashville steel guitar legend John R. Hughey. With all the astounding resources at his fingertips, Burnett, to his credit, never diverted the focus from Welch and Rawlings, whose spare acoustic guitars and high lonesome harmonies dictate Revival's mood and impact.

At the Mucky Duck on Welch's last visit to town, her pairing with Rawlings took on an interesting air of friction mixed with finesse. A few songs into the set, Rawlings, twitching and tense, appeared prone to bust out of his Sunday-go-to-meeting duds and stiff stance for a go at something a little less quaint and a little more savage. Soon enough, though, it became apparent from the body language, satisfied smiles and nervous chemistry exchanged between Welch and her partner that everything was exactly as it should be.

"It wasn't like we just decided, 'Hey, let's write together.' It just progressed to the point where songs were sitting around unfinished and Dave had an idea on how to finish one," says Welch. "All this stuff just kind of evolved. But isn't that always how these things go?"

Gillian Welch opens for Guy Clark at 7 and 9:30 p.m. Sunday, September 15, at Rockefeller's, 3620 Washington Avenue. Tickets are $12.50, $17.50 and $20. For info, call 869-8427.