Chris Hillman's song "Time Between" originally appeared on the Byrds' 1967 album "Younger Than Yesterday," the same album that gave the world "So You Want to Be a Rock 'n' Roll Star." Set amid the rave-up guitar and sci-fi effects of the rest of the album, "Time Between" was a clue, a forewarning that country music would become a crucial element of the Byrds' sound. A year later, the band recorded "Sweetheart of the Rodeo" and single-handedly created the country-rock phenomenon.

Now, 20 years later, "Time Between" has reappeared on the new album by Hillman's new group, the Desert Rose Band. Stripped of the 12-string electric guitar and rock arrangement, the song stands revealed for what it always was: a classic bit of California country and western. That's where Hillman started, and that's where he insists his loyalties have always lain.

"I'm not trying to recapture anything," he says. "This is the same kind of music I was playing in 1962, it's the same kind of music I was playing in 1968. It's just a more evolved form of what the Byrds and the Flying Burrito Brothers were doing. I was never a rock 'n' roller. I flirted with it for a while, but my heart was always with country and bluegrass."

Hillman still bears his rounded crown of brown curls and his neat, tan mustache, but now he performs in a string tie and hand-tooled cowboy boots. His new band includes his longtime friend and banjo player Herb Pedersen, who arranged the vocal harmonies on the "trio" album by Dolly Parton, Emmylou Harris and Linda Ronstadt, and Jay Dee Maness, who has played pedal steel guitar for both the Byrds and Buck Owens.

"I'm not doing this music because I think it will make me a lot of money or because the record company told me to," Hillman says. "I'm doing it because this is the music I love, because these are the songs I've been writing lately. I think this is a very high-energy, very improvisational music. It's an American art form, and I try to do it as an art form."

Hillman grew up in the rural section of San Diego County in the '50s, when a new wave of postwar immigrants brought bluegrass and country music to California from the Southeast. Inevitably, the music changed in its new locale, affected subtly by the dryness and openness of the landscape, the rough and tumble optimism of the valley boom towns and the omnipresent Latino culture. The result was the "Bakersfield Sound," a distinctly California brand of country music personified by Buck Owens.

"Maybe he wasn't even aware of it," Hillman suggests. "But I can hear the influence of Mexican and nortenåo music in Buck Owens. I can hear that stark Southwest sound that started with Lefty Frizzell in Texas. Let's face it -- country music is the white man's blues, and just as the blues had regional variations, so does country music."

Hillman was raised on country/bluegrass legends like Bill Monroe, Flatt and Scruggs, Spade Cooley, Rose Maddox and Pete Seeger, and his first instruments were the mandolin and acoustic guitar. Before he was 22, he had recorded two bluegrass albums with the Scottsville Squirrel Barkers and the Hillmen.

He was picking bluegrass in L.A.'s folk clubs when a fellow folkie, Roger McGuinn, convinced Hillman to trade in his mandolin for an electric bass and attempt a new concept that would be dubbed folk-rock. The Byrds soon included David Crosby, Gene Clark, Michael Clarke, McGuinn and Hillman. Their first single, a cover of Bob Dylan's "Mr. Tambourine Man," went to No. 1.

"Even back then, though, I was the one who was always bringing country music into the Byrds' sound," Hillman recalls. "I was the one who wrote country songs like 'Time Between' and 'The Girl With No Name.' So when we did 'Sweetheart of the Rodeo,' it wasn't the big turnaround everyone thought it was -- it was an extension of something that had been there all along."

With the departure of Crosby and Clark and the arrival of Gram Parsons, the country vote became decisive -- the result was "Sweetheart of the Rodeo." Within a year, Parsons and Hillman left the Byrds to found another important country-rock band, the Flying Burrito Brothers.

"We laid the groundwork for the Eagles, Linda Ronstadt and everyone who followed in our footsteps," Hillman says matter-of-factly. "Now the Desert Rose Band is following in the same tradition. We're just taking it one step further."

Hillman did make several detours back through rock 'n' roll, with stints in Stephen Stills' Manassas, the Souther-Hillman-Furay Band and the McGuinn, Clark & Hillman reunion project. In 1981, feeling burned out by the music biz, he retired for a year to sort things out. He found the perfect antidote in bluegrass, the first music he loved.

"Bluegrass is the foundation of everything," he claims. "It comes straight out of the church, and it represents country music at its purest. If you can play bluegrass, you can play anything."

Hillman's 1982 bluegrass album "Morning Sky" was a critical success, and it attracted the ear of Dan Fogelberg, who wanted to make his own bluegrass album. So Fogelberg invited Hillman not only to play on the 1985 album "High Country Snows" but also to accompany him on the subsequent tour. When Fogelberg came to Merriweather Post Pavilion that summer, Hillman's bluegrass quartet opened the show and then joined Fogelberg for several songs.

That quartet -- Hillman, Pedersen, dobro player John Jorgenson and bassist Bill Bryson -- so enjoyed playing together that they stuck with it back in L.A. after the tour and eventually added Maness and drummer Steve Duncan. This sextet will play songs from its new MCA album when it opens for the Forrester Sisters at the Kennedy Center on Saturday.

"I'm glad I was part of rock 'n' roll during that very creative period in the '60s," Hillman admits, "but I got tired of it. I got tired of the format, the entourage and the wall of amplifiers. I find traditional music far more challenging and rewarding. Besides, it's what I do best."

Richard Harrington is on vacation. His On the Beat column will resume when he returns.