MICHAEL FRANKS makes music you can see: "Blue Pacific," the first album in three years by the jazz-pop singer-songwriter, is an emotional return to his California oceanside roots, and the lyrics are full of "crayon suns," and "opal pools" and "diamond waters," the breezy melodies softly tinted with sky blues and sea greens. Imagine what one of David Hockney's swimming pool paintings might sound like, or one of Richard Diebenkorn's sunny seaside abstracts.

Franks, who appears at Wolf Trap Saturday, has a soft-spoken singing voice that suddenly summons up the essence of California, a sunny, unhurried, frictionless croon, with kind of a sleepy smile in it. That serene voice goes with Franks's easy, no-sweat melodies and almost tropical rhythms. But all this apparent effortlessness is deceptive -- there's clearly some work behind the words. Franks is one of our most literate songwriters, with a rare poetic licentiousness -- you've gotta love the utterly offhand way he tosses off a sly line like "I hear from my ex/On the back of my checks."

Though Franks, 45, now lives in Fort Meyers, Fla., a resort town where, he says, "there really isn't much going on," he remains at heart very Californian: The album credits thank his running coach, vegetarian chef, homeopathic physician and massage therapist, among others. The new album touches on consequential things in his life: There's love and sex, of course -- "Chez Nous" is a sly sequel of sorts to "Popsicle Toes," Franks' left-field pop hit of 1976. "Long Slow Distance," about the rigors and sensual rewards of running (as well as another playful metaphor for sex), might just become the theme song for Marine Corps marathoners in training.

But most of all it's about life on the left side of the country.

"I thought it would be great to do a West Coast kind of album," Franks says. "I grew up there, and I made most of my early records there, up to 'Burchfield Nines,' which was when I moved to New York.

"So I went out to California to write -- I had never deliberately gone somewhere and said, 'I'm going to write in this location.' My wife and I rented an apartment in San Diego, in fact -- about half a mile from the house I grew up in. And it was great to just sort of stare at the ocean and get into the idea of writing and recording."

Schedule conflicts have prevented Franks from taking along on tour the album's lineup of West Coast names, which include pianist Joe Sample, guitarists Dean Parks and Buzz Feiten, drummer John Guerin and Franks's 20-year-old son, Sean, who played cymbals on one track. But opening the Wolf Trap show will be guitarist Larry Carlton, responsible for some of the hottest licks on Steely Dan albums, who sat in on "Blue Pacific." And Franks himself will be playing guitar onstage again for the first time in a long time.

"Once I started to be able to afford to take out these great guitar players," he says, "it seemed kind of pointless to pick up a guitar when you had Steve Kahn up there."

On "Blue Pacific," Franks divided up the 10 songs among three well-known producers, an unusual approach suggested by Reprise Records.

"I had heard from other artists that a lot of problems could arise from that kind of approach, not the least of which is at the end you could end up with material that all sounds different," he says. "But I found it a great way to work. I worked with {jazz-pop keyboardist} Jeff Lorber first, who worked in a totally different way than Tommy LiPuma, who was completely different from Walter Becker at the end. Sometimes when you're working on a record with one producer and you're doing nine or 10 songs, you both get a certain kind of blindness about the last few tracks. Each of these three producers was so focused on the tunes they were doing that each song seemed to be really special and to have its own character."

Becker, who produced Rickie Lee Jones's latest album, is best known as one-half of the '70s studio entity Steely Dan, which, like Franks, pioneered an ahead-of-its-time pop-jazz hybrid.

Franks is preparing to dip a popsicle toe into the theater -- he's recently completed writing and recording "Noa Noa," a musical on the life of Paul Gauguin, the 19th-century painter who left his home and family and split the competitive Paris impressionist scene to paint in Tahiti.

"I had done a tour of Australia 10 years ago and on the way back I stopped in Tahiti," Franks says. "And I got really interested in the idea of something about Gauguin that would be musical. The way he's been portrayed is so unfair. Somerset Maugham did a real hatchet job on him, and there was this film with Donald Sutherland that gave a really strange portrayal of him. And his life seemed so dramatic itself without any embellishment.

"So I wrote a couple of things -- I guess I thought I'd just work on an album from his point of view. And it evolved into a musical. I had seen 'Evita,' which I thought was excellent, and I was encouraged because it was sung from top to bottom, the way I'd like to do this show. I took almost two years off, made recordings of both acts, all the songs."

Along with composing 30 songs -- three of which, "Vincent's Ear," "Woman in the Waves" and "On the Inside" appear on his album -- Franks has conceived the show visually and dramatically, including writing stage directions.

"I have a feeling a lot of that stuff is probably going to be thrown out," he laughs. "I'm fairly ignorant of musical theater. Now it's at the stage where they're talking about a workshop production, for fall next, ironically, in the town I was born in, La Jolla, {Calif.}."

Franks, whose tour T-shirts are screened with some of Gauguin's familiar island images, says his attraction to the painter is complex. "I admire his paintings, of course. And the courage of what he did really impressed me. I think it's kind of a shared fantasy, for people who live in our kind of Western world existence. You hear a lot of people say 'What I'd really like to do is go to some deserted place and be creative.' Of course, I've been one of the lucky ones -- I've been allowed to be creative."