During a hectic afternoon of interviews at the Studio City offices of her co-managers, veteran singer Bonnie Raitt is cheerful and friendly, apologizing for being late and gamely submitting to having her picture taken–a process she clearly finds uncomfortable.

“People tell me not to worry,” she says as the photographer snaps away, because her face reflects her life experiences.

“Yeah, me and Keith Richards,” she scoffs lightly, perching on a conference room table and propping her clunky black boots against the windowsill, her tousled mane of red hair half-obscuring a wry, baleful look.

Raitt, 48, might joke about aging, but she has just made the kind of daring career move that veteran artists rarely even consider–purely for the challenge of it.

Why else would she recruit a new band, try co-writing songs for the first time and change producers for her new album, after nearly a decade of getting hits with her polished, Don Was-produced recordings?

“I wanted to make a left turn,” says the singer-guitarist, settling into a wingback chair. So she enlisted minimalist masters Mitchell Froom and Tchad Blake (Sheryl Crow, Los Lobos) to help her co-produce “Fundamental,” her first new collection in four years.

The album’s primal sound vaguely recalls Raitt’s early-’70s records, roughing up the edges that Was had smoothed out for the multiple-Grammy-winning “Nick of Time” (1989) and “Luck of the Draw” (1991), as well as 1994’s million-selling “Longing in Their Hearts.” (Was also produced Raitt’s first-ever live album, 1995’s “Road Tested.”)

She emphasizes that the change was not about rejecting Was’ approach, but about doing something different. As her co-manager Ron Stone points out in a separate interview, “She’s trying to make it fun for herself, and quite honestly go back to basics in terms of her approach. Don made four albums with Bonnie. She just felt it got a little too comfortable, and she wanted to challenge herself.”

‘Let’s get back to the fundamental things,” she croons on the opening track, her sultry vocal framed by the erotic clatter of her trademark slide guitar. Froom and Blake have made her sound both modern and timeless, tapping the elemental forces channeled by John Lee Hooker, Sippie Wallace, or any of the veteran blues artists she so admires.

“It’s not something that people would’ve normally thought of, putting Mitchell and me together,” Raitt says about “Fundamental.”

“He said, ‘Are you sure your fans are going to want to hear your music the way that Tchad and I will work with it?’ I think my real fans are going to understand and be glad no matter what I do, except hold still. If I just repeated myself all the time, they’d probably desert me, which they should.”

On one hand, the songs on “Fundamental”–which is off to a respectable start, selling more than 150,000 copies in its first three weeks–don’t depart much from Raitt’s usual blend of blues, R&B;, folk and pop. And the lyrical themes explore her familiar touchstones of romance and rebellion. But there’s a bit more immediacy to the delivery, maybe because her voice is more prominent in the stripped-down mix. Or maybe it’s because she’s singing her own words a little more often this time, having written or co-written five of the 11 tracks.

Many of the songs explore the ups and downs of a longtime relationship (she’s been married to actor Michael O’Keefe since 1991), making their appeals with a touching vulnerability. But you’d better believe there’s no begging involved.

“No way, yeah!” concurs Raitt. “I feel only recently comfortable with embracing my female side. Accepting the female part wasn’t even a possibility for me until I was in my 40s. [Growing up] I was a tomboy, because I knew that girly-girls were really wimpy, and they were concerned with stuff that seemed totally [stupid]. I mean, the last time I thought painting my nails was fun was when I was 7.”

Maybe it was because she has two brothers, and her dad–famed Broadway singer John Raitt–didn’t relate to girls very well. She shrugs. “Psychologists could go to town and figure out why I want the validation of being around all guys. I didn’t wanna be a guy, but I wanted to be accepted as equal.”

Gaining the respect of the blues musicians she looked up to, and getting to play with them while still in her early 20s, reinforced her conviction that “the qualities that people come to me for are the things that are only going to get richer with time.” She considers it a blessing that her appeal isn’t tied to being a sex symbol.

At the same time, she wouldn’t dream of labeling any pop sex symbol as less likely to have staying power–at least not anymore.

“Ironically, I said a few years ago that I’m like a character actress; I can get older more gracefully in this culture than Madonna, for example. Then, 10 years later, we see that she’s now going to get older [more gracefully]. So I will never make that comment again, because I said it’s going to be easier for me to be 50 than it will be for Madonna, but I don’t agree with that anymore.”

These days, Raitt’s more inclined to argue that it’s tough for anyone to be 50, especially her friends in the music business. “I’m still secure in my job, and they’re getting the ax. It really makes me upset. It’s because younger bands want to work with a younger head of publicity, or a younger head of video. And it’s not OK for the promotion man to be 55. And that really stinks.”

Raitt herself will be mixing it up with younger artists when she hooks up with the Lilith Fair tour in July, following her current two-month tour of medium-sized theaters.

Although Raitt likes the idea of playing in more intimate settings, she’s quick to note that success has allowed her the luxuries of paying her band a decent wage and taking time off to concentrate on her writing. She took a break before recording “Fundamental,” although she still kept busy with guest appearances on others’ albums and continued to work for causes such as the environment and the Rhythm & Blues Foundation, the musicians’ advocacy group she co-founded. She also was inspired to collaborate on songwriting for the first time.

“I’ve never had anybody pass judgment on my lyrics or my singing, and I’m not that particularly interested in having someone do that,” she says. But she was determined to stretch her abilities. She made the situation a little safer emotionally by working with such friends as Beth Nielsen Chapman, Annie Roboff and acclaimed Irish songwriter Paul Brady.

“After a while,” she says, “you have to forget whether you might hurt someone’s feelings and just say, ‘That’s not what I had in mind’ or ‘I really don’t like where you’re going with that.’ ”

Spending time away from working and writing helped Raitt see life more clearly, says her co-manager Jeffrey Hersh. “She could see what her life was like without being [so involved in making music],” he says, “and have experiences she could write about.”

Adds co-manager Stone, “She’s always been so respectful of great songs, it’s been hard for her to venture into that territory in the face of the caliber of songwriting she’s used to. As she’s been more accepted as an artist, her confidence about her songwriting has allowed her to collaborate more easily.”

Brady, who co-wrote the album’s buoyant, Stones-esque rocker “Blue for No Reason” and the first single, “One Belief Away,” served as a particular inspiration and mentor. “I was hearing things in my head that I actually couldn’t play,” says Raitt, “so he helped me bring them out.”

But Raitt is apprehensive that “Fundamental” could be more vulnerable to criticism than her previous albums. “I don’t write songs easily or that much,” she admits.

“Usually if you finally get some success, [critics] start tearing you down,” she says. “For the last few years I’ve just been waiting for that big boulder to hit me, and it hasn’t hit.”

Raitt needn’t have worried. Though The Times’ Marc Weingarten gave the album a mixed review, most of the notices have been strong. “In a musical world where ‘everything’s carefully prearranged,’ Raitt has thrown a Birkenstock in the works, and the clatter sounds like life itself,” declared Rolling Stone.

In fact, she seems more likely to surprise both followers and critics these days. For example, traces of world music in her work are echoing louder and louder. “I listen to so much African music and so much Celtic music,” she says, that she’s beginning to feel restricted by 12-bar blues. She draws inspiration from the early-’70s musical hybrids created by such favorite artists as Little Feat and Ry Cooder.

“They weren’t trying to just re-create something that was originated by somebody else,” she says. “They synthesized all this really uniquely American stuff into this kind of music that was totally natural. That’s what I am aspiring to do with the music that I write.”

* Bonnie Raitt plays June 12-13 at the Pantages Theatre, 6233 Hollywood Blvd., 8 p.m. $27.50-$47.50. (213) 468-1700.