There's a fantasy Jenny Lewis that has grown in fans' minds over her four albums with Rilo Kiley and two solo records (the second of which, Acid Tongue, is out this week). This is the ballsy, lusty Lewis of songs such as "15" (in which she revels in portraying Southern jail-bait), who flashes her knickers in sultry photo-shoots and gigs, and once felt moved to record a song nude. Put out to work by her mother as a child-actress in Hollywood, aged four, she worked alongside Lucille Ball, and Angelina Jolie. This glamorous CV has made major labels think she'll make it big any day now, with or without Rilo Kiley, who've toured with Coldplay. Friends and fans including Elvis Costello, the Black Crowes' Chris Robinson, Zooey Deschanel and M. Ward are on Acid Tongue.
The fantasy falls apart when the five foot-nothing Lewis meets me in North Hollywood. She's wearing a black mini-dress, little belted boots, and white socks. But what's more striking is her wariness as she lets her defences down inch by inch. The same process has been under way musically since her 2006 solo debut Rabbit Fur Coat, which clarified her sound, putting her crooning country-soul voice at its heart. Rilo Kiley's last album Under the Blacklight (2007) and the rough and ready Acid Tongue continue her growth.
I meet her down an alley one sunny lunchtime, in a hidden, funky studio from the early 1970s, a little past Muddy Waters Drive. Tree-stumps, lanterns, old sofas and a rocking chair litter the place. When her band turn up later, the pet-names they use for her are jokily star struck ("Like, what is this, J-Lo?"; "Ready for your close-up, Mr DeMille"...).
Though she has just finished a tour with Rilo Kiley, that band have an uncertain future. Yet their ability to make her songs sound like uplifting pop has been crucial.
"That's what we do best," she agrees. "They've always brought this really poppy, upbeat sensibility to these weird lyrics that I don't think even they really understood all these years. I don't know if they really heard most of them."
"The thing about Rilo Kiley," she continues, "is there are three people in that band who have struggled with depression over the years. And when the three of us are together, we kinda take it south. I've gone through terrible periods of depression. But, at the core of my being, there's a strange, out-of-place optimist. Despite what I'm feeling, I'm always able to get up and do my job. Which means the world to me. It sounds cheesy, but music has saved me in a lot of ways. If I had just continued acting, I don't think I would be alive."
This depression suggests itself in ambivalent songs set in a godless, loveless world. "How sad!" she says. "You know I've felt how I feel today since I was eight years old. I've always felt lonely, even if I'm in a great relationship, or surrounded by my friends and family. I don't know what happened prior to that that made me feel that way. But I've been the same person since 1982."
That was when she became a full-time television actress, five years after her parents divorced. They were a double act in showbiz's twilight zone. After divorce, dad disappeared. Mum, unemployed in LA, put her toddler to work on TV; treating "your daughter as your spouse", as the mother in "Rabbit Fur Coat" is advised. The raunchy matricide fable "Jack Killed Mom" develops that theme on Acid Tongue. More songs are about her dad, Eddie Gordon, a surprise guest-star on harmonica.
"He was ill last year, so we started speaking to one another," she explains. "There were no hard feelings. He just wasn't around. Every couple of years I'd get a postcard from the road – a picture of him standing next to a giant ice-sculpture of a crab, in Alaska. He was a very mysterious character. But I thought this was the right time to bring him in."
The first hint of change with her parents seemed to come in Rabbit Fur Coat's "The Charging Sky": "Have I mentioned, my parents are getting back together/ 25 years of spreading infection..."
"That verse [which begins "Still they're dying on the dark continent"] is just as much about Africa as it is about my parents. But sadly no, it's not true."
Acid Tongue's nine-minute centrepiece "The Next Messiah" meanwhile offers a sprawling portrait of footloose masculinity, and bitter relations between a "con-man" and a "cocktail waitress who thought she was an artist". This hustler sounds very like the dad who sent her postcards from the edge of the world.
"When someone isn't around you create what you imagine your father might be – 'a race-car driver, a four-leaf clover'," she quotes the song.
She encrypts her confessions. "I try to protect myself," she admits. "I will often go back and change the names..." To protect the guilty? "Exactly! Including myself."
What role, then, do her parents play in her songs? And suddenly, as if a key has been turned, her defences drop. "I write mostly about my parents," she says. "Because I just don't know them very well. And I'm still trying to understand what happened [with the divorce] and why. It's this blank slate, I can't even remember what happened. But for some reason, these two people are so incredibly strange and funny and beautiful and messed up, that I want to keep writing about them... and maybe figure out who I am in the process."
The cameras that stared at Lewis through her adolescence perhaps explain her shyness since. It took more than a decade as a musician for her to release a record under her own name. It's as if some vital emotional growth was held back, in her Hollywood childhood. "I feel like I never got a chance to be a child," she agrees. "I wouldn't change it for the world. But when you're a kid supporting your family, you're forced to keep your eye on the prize. I have a great work ethic, from watching Lucille Ball, not necessarily my own family."
For all the Hollywood surrealism of that line, the dream factory powering Lewis's songs is a decidedly more private affair. "I've consistently tried to create an alternate reality," she says. "I'm removed in my real life, and unable to express certain things face to face. So I have always found myself in this fantasy world. That's why I started writing songs and stories from a very young age. I'd much rather walk around anonymously cooking up tales than face the people that I have known forever."
"The Angels Hung Around" (on Under the Blacklight) shows her typically ambiguous attitude to LA, where she sings of being "whored" and "gored". But, outside Hollywood, in the San Fernando Valley suburban sprawl where she began, is a different story. "There's a class distinction," she explains. "Growing up in the Valley, the goal is to move over the hill. I did when I was 16. And last year, at 30, I moved back. I needed to get closer to my upbringing, to continue to write about it. I don't feel comfortable in Hollywood, I never have. I went to Beverly Hills High School for a year on a fake address, and got kicked out for living in the Valley. I was so relieved. Now I wander the car dealerships and the air-conditioned malls and the parking lots, and get inspired."
The deepest, darkest theme in her lyrics recurs on "Badman's World", one of several songs partly about suicide, in which a man's face turns blue, and she decides: "I'll never forgive what you put us through." I ask where these lines come from.
"I don't know where that comes from. Perhaps it goes back to post-1982. Being around people that had lost their will to live. Which is really heavy when you're a little kid. To really not understand what's going on, but to be faced with someone who has clearly given up hope. It left me with this weird, skewed perception."
Exactly what shocks to her child's system 1982 contained, Lewis hardly seems to know herself. "Traumatic moments," she suggests, buried deep. "I'm sure tons of people have experienced them. But things that changed me, forever. That being one. My only LSD experience being another, which is why I wrote 'Acid Tongue'." She sidesteps eagerly, to an acid nightmare when she was 14. "I found the psychedelic experience to be totally terrifying. My friend was chasing me around the house with a knife. It was actually like a scene out of Fear and Loathing in Las Vegas.
"I don't need psychedelics. I've lived a good and strange life. I'm a late bloomer, in every aspect. I'm a slow-moving train. But I'll get there eventually. I like people, that's the thing. I'm the most negative optimist you'll ever meet. And making this record is the freest I've felt."
Her band are filing in, and for the next few hours, I'll watch the other Jenny Lewis, eyes closed and hair swinging, abandoned to a thunderous blues beat. But the clues in her remarkable songs still bug me.
What did her parents think, I finally ask, of that line about "25 years of giving disease"? It sounds a plain, bitter statement of their divorce's effect. "It's also about Africa," she reminds me, almost keeping a straight face, shutting the book on her secrets.
'Acid Tongue' is out on Rough Trade