With more than a decade of making music together, the members of Slightly Stoopid have perfected one of the rarest—and most valuable—skills a band can develop: the art of the stealth groove, that knack for quietly—almost innocently—sliding into a song and utterly lassoing anyone within earshot by mid-song. That's where the band has come to reside, musically: deep in the pocket, that ever-elusive, funky trench where a band can entrance an audience, hypnotize it and hold on to it until the set or CD is finished.

And that's just what the band does on its sixth studio offering, Chronchitis , another collection of hypnotizers built on a bedrock of nasty, oceanic slabs of dubby bass and meditative vocals. A cornucopia of styles and influences—a little sweet lullaby here, a dose of Kingston rocksteady there, a fat chunk of hip-hop there, a slight Eastern groove way over there— Chronchitis is the fruit of sessions in Austin, Los Angeles and Redondo Beach, helmed by a crop of top-shelf producers: Paul Leary (Butthole Surfers, Meat Puppets, Sublime), Mario Caldato Jr. (Beastie Boys, Jack Johnson), longtime band associate Miguel (Sublime), and Chris D. (G. Love).

Featuring guest turns from Guru of Gang Star ("The Otherside"), G. Love (" Baby I Like It"), Angelo Moore of Fishbone ("Ever Really Wanted") and the Beastie Boys' keyboardist Money Mark, Chronchitis is another volume in the band's string of blissed-out party records. It's the ultimate soundtrack to a momentous summer evening, an instant beachside keg party filled with good drink and smoke and a psychedelic sunset.

"I think this is our most mature record," says co-frontman Miles Doughty. " We're getting older as people, as musicians, and, honestly, I think this record reflects everything from life to love, madness, good times, bad times, it's just all incorporated in this record. It's life through our eyes."

The disc is comprised of all the ups and downs one might experience during that great night out: there's smooth acoustic moments like opener "Anywhere I Go" (the soundtrack to a great, mellow buzz), full-on, rump-shaking, grin-spreading jams ( "Ever Really Wanted") and the easy-rolling, end-of-the-party/last-call, chill, pot-bust cut "2 am," all awash in Jamaican horns and rich organ swells.

"That's just a bad-attitude-toward-the-cops song," says co-frontman Kyle McDonald, who shares vocal, bass and guitar duties with Doughty. "It's about the police holding up the innocent, when they could be doing better things with our tax money instead of going after skateboarders, pot smokers and people who park in the wrong spot. It's about a lot of people's lives, a lot of people go through that situation where they're just sitting in their house and in comes someone who just ruins them over what, a plant?"

"I like that song, and I really like ‘Girls so Fine,' which is just about my girl, and kind of about when you need someone… There's all sorts of stuff on this record. It's a good one to steal. If you're gonna steal one, steal this one."

Issued through the band's Stoopid Records/Controlled Substance Sound Labs, Chronchitis again finds Doughty, McDonald, drummer Ryan Moran and percussionist Oguer Ocon (formerly of the B-Side Players) and the new horn section of C-Money and Dela (from John Brown's Body) carefully and rather expertly blending influences as diverse as Cat Stevens and Lee "Scratch" Perry. If some songs are entrenched in mid-70s roots reggae, others blend both classic and third-generation SoCal rocksteady. In the meantime, wee touches of Blues Traveler and Dr. John occasionally emerge, however unintentional.

"With Chronchitis , we really just went into the studio open minded," says Doughty. "I think the best music always comes from the acoustic guitar first, so it was kind of cool that when we made all the music, the acoustic guitar was incorporated with so much of it. Each guy likes different kinds of music, so when we write, we'll mix all that shit together, whether it's folk music, reggae music, metal, funk, whatever."

The disc is the latest installment in a subculture, or subgenre of musicians that, like Slightly Stoopid's grooves, has rather quietly become a chilled-out force to be reckoned with in the music industry. With peers like Sublime, Jack Johnson, 311 and G. Love, Slightly Stoopid have proven a cornerstone of a new generation of bright, mellow albums full of acoustic grooves, love for reggae and select ‘70s California singer/songwriter records. Just when the mainstream wasn't looking, Slightly Stoopid has registered more than a decade as a band, while amassing its own, unique group of devotees—lovingly dubbed Stoopidheads and/or "Ese Locos" —and selling hundreds of thousands of records in the process.

That trip began in 1995, when Doughty and McDonald (childhood friends who grew up in Ocean Beach, CA) caught the ear of late, beloved Sublime frontman Bradley Nowell, who signed them to his Skunk Records label, which issued the band's first two discs: 1996's punk-tinged Slightly Stoopid (featuring a guest vocal by Nowell himself) and 1998's surf-inspired The Longest Barrel Ride .

While growing its fanbase beyond its native Southern California , Slightly Stoopid in 2001 self-released Acoustic Roots: Live and Direct . The 40-minute acoustic set, captured at San Diego 's Rock 105.3 radio station, was a precursor to 2003's Everything You Need (Surfdog), a musical departure for the band that sold more than 100,000 copies. The band's mix of rock, reggae, funk and blues coalesced two years later on Closer to the Sun (Reincarnate/Caliplates).  With songs such as "Bandelero," "Somebody," and "This Joint" and a collaboration with the great dancehall reggae legend Barrington Levy ("See No Other Way") the disc quickly became a fan favorite. Helmed by Miguel, it also featured contributions from reggae producer Scientist, an understudy of the iconic Jamaican boardsman King Tubby.)

In 2006 the band treated fans to an electric live album ( Winter Tour '05-'06 ) and their first DVD, Live In San Diego , a hometown bash featuring some 20 songs. For anyone who hadn't yet seen the band live, it was/is a slice of Stoopidhead love, and something that the band has become pros at: Each year, Slightly Stoopid plays some 150 gigs, their headlining spots spreading to two-plus hours of improvised jamming. Says McDonald: "It's all about the grass roots style: You've got to tough it out, got to get your hands dirty touring and making music."

Along the way, the band has taken its live show to as far-away shores as Australia, Japan, Guam, Amsterdam, Portugal and Denmark, the U.K., Germany, Holland and the Dominican Republic, and supported the likes of the Dave Matthews Band, Damian "Jr. Gong" Marley and the Marley Brothers, Sublime, The Roots, G. Love, Toots and the Maytals and Pennywise.

The band has evolved into one of America 's most successful independent touring bands. In 2006, touring industry trade magazine Pollstar ranked the band as one of the Top 50 draws in the States. It's a distinction hard-earned over the past decade, as the band has honed its breezy blend of everything from the Grateful Dead and Dire Straits to Joe Higgs and Delroy Wilson. And it's been one not only enjoyed by Stoopidheads, but also Hollywood : The band's music has been featured in such TV shows as The OC and North Shore and in such movies as Step Into Liquid and Norbit and She's the Man .

Says Doughty: "We're really a band that's just about having a good time, making music that we love and just having fun. For us, positivity goes a long way."