Linda Ronstadt's pop profile has been so low in recent years that some of her fans may have thought she had gone into semi-retirement.

One of the biggest selling and most acclaimed singers of the '70s and '80s, Ronstadt has been noticeably absent from the pop charts, the mainstream concert stage and the media. But it has been no Garbo move.At an age when most veteran pop artists are recycling the old hits or cutting back on their musical output, Ronstadt, 47, is in the studio almost constantly, working on a wide musical spectrum.

Since 1989's "Cry Like a Rainstorm - Howl Like the Wind," her last collection of pop tunes, the Tucson, Ariz., native has recorded two albums of her own in Spanish and produced albums for Aaron Neville, David Lindley, Jimmy Webb and the Mexican group Mariachi Los Camperos, most of it at director George Lucas' Skywalker Studios in Marin County, Calif. It's a musical vision wide enough to establish her as a true pop renaissance woman.

In the '70s, Ronstadt wasn't just a hit-maker, but a symbol - with the Eagles and Jackson Browne - of the introspective, country-flavored sound that was identified with the region in that decade. The California connection was compounded by her highly publicized romantic link with Gov. Jerry Brown. There were even rumors of marriage during one of Brown's presidential bids.

But those times weren't quite so magical for Ronstadt. She was never comfortable, she says, singing rock 'n' roll, nor did she feel at home in Los Angeles. Rather than sticking cautiously with the pop-rock style that had brought her fame, Ronstadt boldly accepted the role of Mabel in Joseph Papp's 1980 Broadway production of Gilbert & Sullivan's "Pirates of Penzance."

Feeling liberated, she proceeded in the '80s to record three collections of pop and jazz standards, a country album with longtime pals Dolly Parton and Emmylou Harris, and the first of her Mexican music albums.

The dark-haired singer will continue to make occasional pop albums - the new "Winter Light" features songs by some of her favorite writers, including Webb, Harris and the McGarrigle Sisters. But not even the 2 million sales success of "Cry Like a Rainstorm" could lure her into returning full time to the style.

Ronstadt, who moved to northern California in 1988 during her five-year relationship with Lucas, now lives with her 2-year-old adopted daughter in a Victorian house in chic Pacific Heights.

On the eve of the new album's release, she sat in the living room of the four-story house and spoke about the years of pop stardom in Southern California and her restless search for musical satisfaction.

Q: How did you feel being a symbol of Southern California pop-rock in the '70s?

A: The funny thing is Southern California always seemed like such a foreign place to me. I was homesick for Tucson and wishing that I could be back playing the Mexican music and traditional music that I made with my brother and sister.

When I started recording with (the '60s Los Angeles trio) the Stone Poneys, people seemed to like us, but I was impatient with the music because it didn't feel as good as what I left behind - and I continued to feel that way all through the '70s when I was on my own. I kept trying to learn to sing better, but I don't think I ever did get much better.

Q: You were probably the most critically admired singer in pop and rock of the decade and yet you say you didn't feel comfortable with your music?

A: Most people came to rock 'n' roll through blues or rhythm & blues or gospel. I didn't have that background at all, except for what I heard as a kid on radio. I sang Mexican music, and that's what my best voice was, that "ranchera" style, Mexican country music. That's where my sense of phrasing and rhythm was based.

Q: But didn't the sales and acclaim convince you in the '70s that you were doing quality work?

A: No, because I could hear what it sounded like and I didn't think it was very good. I often thought the album covers were better than the records. I was very frustrated musically. I thought the production on "You're No Good" (her 1974 breakthrough No. 1 single) was very good, but I didn't sing it very well. As a song, it was just an afterthought. It's not the kind of song I got a lot of satisfaction out of singing.

Q: What led you into rock in the first place?

A: It was through American folk music because Bud & Travis (a folk music duo in the '60s) played in Tucson a lot, and they did Mexican stuff as well as American folk.

We liked what they did so much that my brother, sister and I started a trio, the New Union Ramblers. We played around Tucson, doing folk music in English and in Spanish. My goal in those days was just to play the Ash Grove in Los Angeles because that was the center of folk music at the time.

But then my brother went to work for the police department and my sister had a bunch of kids, so they weren't able to go on the road. Bobby Kimmel, who used to play bass for our group, said he knew how to get work in L.A., so we headed there (in 1964).

Q: What gave you the nerve to shift emphasis in your career? Don't you see how a lot of people would have let the acclaim and sales seduce them into staying in the pop world?

A: I didn't see going to New York to do Gilbert & Sullivan as a risk. I saw it as a chance to enjoy music more. I wanted to sing in a theater that was built for music, not a coliseum, and I wanted to learn more about singing. Realizing that you can study music is foreign to a lot of pop singers, who grow up on the idea that everything has to be instinctive. That precludes the thought you might be able to actually practice and train and learn and define the subtleties.

Q: What was the impact of "Pirates of Penzance" on you?

A: It opened everything up. Once I did the Gilbert & Sullivan stuff, I wasn't about to turn back and ever go back to music that was unsatisfying. That gave me the confidence and opportunity to do an album of pop and jazz standards, and then the Mexican music.