"THAT WAS THE SCHOOL NURSE on the phone. My son starts school today and he has asthma..." A gracious if somewhat harried Liz Phair is trying to balance the duties of motherhood with a busy day of interviews to promote her new release, Somebody's Miracle (Capitol). Her most acoustic guitar-based album to date, it is also her most mature work -- tinged with melancholy and the kind of bittersweet introspection that sets in when a person reaches the ripe old age of 38.

"There's a sense of regret to some of the songs," says Phair. "That kind of sentimentality you get in midlife."

The wistful, vulnerable Liz Phair of Somebody's Miracle bears only a slight resemblance to the feisty, foul-mouthed alt-rock chick who debuted in 1993 wiht Exile in Guyville, a feminist update of the Rolling Stones' Exile on Main St. On that disc, and the two that followed -- 1994's Whip-Smart and '98's Whitechocolatespaceegg -- Phair delivered blunt observations on sexuality from an anti-romantic, wryly sarcastic perspective. Back then, she dressed down in standard-issue Nineties riot grrrl wear and drove her point home with lo-fi grunge electric guitar.

But as the new century dawned, Phair changed her plan of attack, drafting mainstream hit squad the Matrix (Avril Lavigne, Britney Spears) to produce and co-write half the songs on her self-described "comeback album", 2003's Liz Phair. Grunge diehards were truly aghast at the disc's slick production values and the artist's sexed-up image. Phair remains both amazed and disappointed at her longtime fans' inability to penetrate the album's glossy surface to see its essence.

"People get so hung up on production," Phair says disapprovingly. "Production is kind of like what clothes you're wearing, as opposed to what kind of person you are. It's more the shallow element of a record. So for me, it's just like, 'Yeah, I was dressed up like this for that record.' But what matters to me are the songs -- how I play them guitar and what I'm singing."

As if to prove this point, Phair embarked on a much-publicized and well-received acoustic tour last year, in which she performed her songs with only co-guitarist and boyfriend Dino Meneghin backing her up.

"It was partly a reaction to the critical reception of the last record," Phair admits. "Because when you hear those songs acoustically, you hear why they're just Liz Phair songs. Stripping away the production helps people get a sense of what they really are. People get scared off by big noises. So it was good to come in with an acoustic guitar and say, "Look how well it all fits together.'"

Somebody's Miracle is in many ways an outgrowth of that tour, particularly her acoustic pairing with Meneghin, who produced some of the album. "The approach we took on some songs was to start by recording just Liz and me playing acoustically in a room without a click track or anything," he says. "We would build a track around that, and then go back and replace our parts. Liz is an incredibly accurate guitar player whose timing is very consistent. So not having a click track wasn't a problem -- the drummer just followed her guitar."

While Somebody's Miracle presents a newly vulnerable Liz Phair, it also resurrects an agitpop strategy from her early career. Just as she used the Rolling Stones' Exile on Main St. as a template for her own Exile in Guyville, she employed another classic Seventies album, Stevie Wonder's Songs in the Key of Life, as the tutor text for Somebody's Miracle.

Darker and less "dressed up" than its predecessor, the understated, acoustic-tinged arrangements on Somebody's Miracle provide an excellent backdrop for Phair's emotional songs, allowing her free rein to explore a host of thorny adult issues, from romantic disillusionment to alcoholism to spirituality.

GUITAR WORLD ACOUSTIC How did Stevie Wonder's Songs in the Key of Life influence Somebody's Miracle?

LIZ PHAIR It started out the way Exile in Guyville did with Exile on Main St., though it didn't wind up that way. But Songs in the Key of Life is what spurred me on. That album was on my mind as I was coming up with songs. It suggested a message for me. This album is about wanting to share things from my life that may or may not be flattering or pretty, but doing so in a way that's hopeful and life affirming.

GWA You set that tone right away with the first song on the album, "Leap of Innocence". It conveys a sense of lost romance, of something too fragile to survive in a world going to hell. At the same time, lines like "I had so many friends in rehab / A couple who practically died," are jarringly direct -- something you've always been known for.

LIZ PHAIR Yeah, that sort of thing makes a return on this record. And I think that's what Songs in the Key of Life really helped me with. It brought me back to the sense that sharing your own experience can be more universal than trying to sound universal. Sometimes being more specific about your own experiences can be more resonant.

GWA You seem to know just when to say something right out, rather than relying on a metaphor.

LIZ PHAIR Ah, that's the Chicagoan in me. It's really a Midwestern trait.

GWA Did you write the new album's "Everything to Me" specifically to be a hit single -- the melody, the lyrics?

LIZ PHAIR No. It's really funny, because actually we put together the song "Giving it All to You" with that in mind. "Everything to Me" was this little tune that we completely forgot about because we figured, "Oh, this is too dark, lyrically. It's just too depressing." We literally didn't even turn it in to the label. We gave them "Giving It All to You" and "Count On My Love", which had a different chorus at that point. Those were the songs they considered as possible singles. Then [producer] John Shanks just sort of remembered "Everything to Me", and he sent it out to some keyboard friend of his to see what he could do with it. He kind of fussed it up and brought it back to life. And I got this call one day -- actually many calls -- saying, "Oh my God, this song! The label's going crazy. They love this song!" And I'm going "What song?"

GWA Where did the song "Table for One" come from?

LIZ PHAIR From the personal experience of someone I know who battled alcoholism. It was something I saw happen. I wrote it song when I was still working with Songs in the Key of Life concept. I was trying to make my own "Village Ghetto Land". And that's the most devastating thing I can bring to bear from my own personal experience.

GWA Did you always envision that song being recorded that way -- a lyrical, bittersweet waltz sung to the accompaniment of a nylon-string guitar.

LIZ PHAIR Yeah. In a way I wanted the music to counteract the lyric. It sort of has a drinking song feel, that 3/4 time. But it also has that Latin flavor -- kind of like a mournful mariachi band.

GWA Who played that that lovely nylon-string guitar part?

LIZ PHAIR That was Dino. He did the first two verses perfectly on an earlier demo. But he just did them on a steel string, recorded direct. So when he did the real take, on a Ramirez nylon-string, he had to transcribe his part from the demo and read it in the studio.

GWA Do you play a lot of acoustic guitar on the album?

LIZ PHAIR Oh, I'm all over it, but most of it got buried in the mix. That's what always happens. Every producer always starts out saying, "Yes, we should have your guitar," and by the end of the project it's gone. But yeah, I have a specific part in "Table for One". And in "Leap of Innocence" there's a riff of mine that you can't really hear. "Everything to Me" has a whole bunch of guitar riffs I do that are really the basis for the song.

GWA What role did the acoustic guitar play in your early musical development?

LIZ PHAIR I originally learned on acoustic, studying classical for a year and then folk for about two years. It wasn't until I got to college that I got my first electric, my white Fender Duo-Sonic. I used to write songs on electric guitar a lot. But that was when I could be in my house with a little amp. I travel so much these days that I write on acoustic now. Some of this album was written on my last tour, for the Liz Phair album. I'd never had a tour bus before that album. And I learned that writing songs is one of the things you can do when you get offstage, have a lot of adrenaline and can't fall asleep. I think it makes a big difference.

GWA What acoustics did you use to write the material for the album?

LIZ PHAIR I have a Taylor and a Yamaha CPX-15M; I like both of them. The Taylor is more intimate and rich-toned, while the Yamaha is more camp-firey -- it really projects. I'm trying to get Yamaha to make a 3/4 shrinky-dink version of the guitar I play because it really hurts my hands and back to have to play a guitar made for a larger person. The body's a little too big. A teenage model, or a pre-teen, would probably fit me really well.

GWA So tell me, is Somebody's Miracle a coming out party for a new, mature Liz Phair?

LIZ PHAIR It probably is accurate to say that.

GWA You're definitely dealing with some midlife issues.

LIZ PHAIR Yes, I think this is midlife stuff. Very much so. Not necessarily polarizing. Understanding multiple sides to an issue. That's something new for me.