Kelly Willis may have grown up on a tree-lined street in Annandale, but deep down, she's a good ol' country girl.

The 21-year-old beauty belts out those woe-is-me country tunes with a richness and sincerity that recalls C&W legend and sister Virginian Patsy Cline.

Pretty amazing for someone who at 16, on a lark, decided to try out for lead singer in a local rockabilly band called the Fireballs.

"They needed a singer," says Willis, "and I filled the gap."

Shortly after she graduated from Annandale High School in 1986, the band moved to Austin, Tex. The musical union didn't last too long, though, and Willis and her boyfriend, Fireball drummer Mas Palermo, formed another group with guitarist David Murray, pedal steel guitarist Michael Hardwick and bassist Brad Fordham.

Radio Ranch started out doing rockabilly covers. "I was really influenced by Wanda Jackson. She was a rockabilly queen," says Willis. But eventually the band developed a country repertoire. "It seemed like a natural progression," she says. "We didn't start out saying that we wanted to do that. It just ended up that way."

Comparisons to Cline aren't by chance.

"I had my Patsy Cline period," Willis says, readily. "That's all I listened to. You know, when {the film} 'Sweet Dreams' came out. She floored me."

Now Willis is flooring the critics -- one wrote that she sings "wildly, like an angel with hell-scorched wings" -- as well as herself. When she speaks, she talks big, but there is an innocence in her voice, almost a gawkiness, that comes through, as if she keeps surprising herself.

"There is no way I could ever stop doing this," she says. "Making music is something that once you get it in your blood you can never get rid of it. I'll definitely be doing this forever -- probably."

Kelly Willis and Radio Ranch are performing at the Birchmere Tuesday night at 8:30. Tickets are $10 and available at TicketCenter. For information, call 549-5919.