Could there be a more intimidating musical task than the one Brian Wilson took on five years ago when he decided to resurrect his storied masterwork "Smile," the long-abandoned Beach Boys project that had plunged him into an abyss of psychological torment?

Well, how about completing "Smile" to widespread acclaim, only to find himself face to face with perhaps an even more daunting challenge: "What next?"

Wilson's answer arrived Sept. 2 with "That Lucky Old Sun," the next step in the unlikely return of the musician whose life virtually created the blueprint for the rock 'n' roll prodigy-cum-flameout.

The new album is another song cycle, a loosely thematic work that examines and revels in life in Southern California. It celebrates a culture that Wilson helped define in the 1960s with his ebullient songs of surfer girls, sandy beaches and endless good vibrations.

"Smile" was perhaps the most ardently debated "lost" album in pop music history before Wilson revived it; by comparison, "That Lucky Old Sun" arrives with no history and infinitely fewer expectations. That made it more fun to create for the 66-year-old sole surviving Wilson brother — Dennis, the band's true beach boy, drowned in 1983. Sweet-voiced Carl died in 1998 of cancer.

"This is more of a pop album than 'Smile' was," says Wilson, striding the perimeter of a neighborhood park in Los Angeles.

After completing three miles around the park — he'd already logged two that morning — he steps back into his sporty 2006 Mercedes coupe and tools up the steeply winding roads leading to his favorite deli, not far from the hilltop home where he and his wife, Melinda, have lived for 13 years.

Does he know how much his music has meant to so many people over the years?

"Not really," he says matter-of-factly. "I'm not sure what it means. I would imagine they think some of it's pretty good."

Nutrition and fitness, issues that loom prominently in his life these days, figure into a couple of the songs on "That Lucky Old Sun," including "Morning Beat" and the rock march "Oxygen to the Brain."

"You could do a Brian Wilson compilation of exercise songs," says Scott Bennett, the multi-instrumentalist who wrote many of the lyrics for Wilson's newest songs.

Although Bennett has been part of the Brian Wilson band since he put it together in 1999 to make his return to the concert stage, it was only last year that he and Wilson started writing songs together.

Wilson came to Bennett's home studio with a new song he wanted some help on, liked what Bennett came up with and just kept coming back with more songs.

"He was in an intensely creative place," Bennett says. "In my nine years with him, I hadn't ever seen him this on fire."

Initially, Wilson wanted to make a new album of upbeat rock numbers. Then he got a call from officials at the Royal Festival Hall in London, which had hosted the world premiere of "Smile" in 2004. They asked him to create a work and premiere it there, requesting that it follow the "Smile" blueprint.

Wilson turned to his "Smile" lyricist, Van Dyke Parks, for a string of narrated vignettes about life in Southern California. Wilson and Bennett then set about adapting some of the songs they'd already been working on.

He also sings of the band he formed so long ago with Carl and Dennis, cousin Mike Love and their Hawthorne neighborhood pal Al Jardine in the bittersweet ballad "Southern California." The album's emotional centerpiece is "Midnight's Another Day," a solo piano-driven ballad that opens with a disarmingly honest self-assessment.

"That Lucky Old Sun" is punchier and lyrically more straightforward than "Smile" but less deeply resonant. It's the difference between the work of a 24-year-old wunderkind and a 66-year-old battle-scarred survivor.

"As you get older, you appreciate the little things more: a walk in the park, a sip of champagne, a kiss on the cheek ... those things you might not have noticed when you were younger."

Those near Wilson credit Melinda's steadying influence for his return to music. He doesn't mention her, but it may well be that she's on his mind.

"Do you believe in guardian angels? I do," he says. "I believe they're around us all the time, watching over us and protecting us."