When Blues Traveler plays its last song Sunday night and the lights come up at Coral Sky Amphitheatre in West Palm Beach, the HORDE will disperse for 1996, leaving the music world to wonder what the organizers of this roots-rock extravaganza can possibly do for an encore.

The HORDE Festival’s date in South Florida is the closer in a 42-show tour that has rivaled, if not surpassed, Lollapalooza for sheer buzz and box-office blast. Can they do it again next year? Indications are they’ll be back to try.

The ’96 campaign has been the biggest and most ambitious yet since Blues Traveler front-man John Popper – assuming the role of rock impresario – first launched HORDE (Horizons of Rock Developing Everywhere) in 1992 with a pair of one-week tours.

The lineup then featured a handful of rootsy bands that were in their element playing live: Blues Traveler, Aquarium Rescue Unit, Phish, Spin Doctors and Widespread Panic. The eight shows – four per tour – lost money and labored in the shadow of Lollapalooza, the heavyweight festival launched by then-Porno for Pyros bandleader Perry Farrell.

But Popper stuck by his vision of a free-spirited, jammer’s caravan featuring bands that love the spontaneity of the stage. And year by year, HORDE grew, attracting more bands, bigger names and larger crowds. Between 1993 and 1995, the tour’s average attendance per show shot up from 6,400 people to 16,000.

Today, the portly Popper finds himself presiding, daddylike, over what appears to be one big happy family.

“It’s a great environment,” says Nil Lara, the Cuban pop-rock trailblazer who was invited aboard the HORDE ’96 bandwagon for the home stretch. Lara, touring behind his self-titled debut album for Capitol Records, shares the second stage with four other acts and reports, “All the second-stage bands have gotten pretty close.”

Dave Boquist of the high-lonesome rock group Son Volt feels the same vibe.

No discord

“A lot of other bands that we’ve talked to, they’re people that we can generally relate to,” Boquist says. “That helps people feel like they have some commonality. I’ve never fit in real well with masses of crowds. I get a little claustrophobic – not onstage. Offstage. The stage is a safe place for me. I’m just talking about the whole thing, walking around with hundreds of thousands of people, or 50,000, or however many there are … But the people who run this thing have been very neat, really good people. And it’s a really good atmosphere.”

The HORDE alumni roster grew to include some of the most prestigious and successful rock and pop artists of the 1990s, including the Dave Matthews Band, Black Crowes, Joan Osborne, Natalie Merchant and Sheryl Crow; up-and-comers Morphine, Me’shell NdegeOcello, Big Head Todd & the Monsters, G-Love & Special Sauce and Wilco; and grand old rockers King Crimson and the Allman Brothers Band.

And while Lollapalooza organizers were getting sidetracked by arguments about the correctness of its lineup, with Farrell himself charging the “alternative” festival had lost its edge, HORDE – which had never pretended to be anything except an old-time rock ‘n’ roll show – rumbled across America without a cloud on its horizon.

With its laid-back hippie aesthetic and its stage-savvy bands, HORDE began developing its own little tradition and history. The mantra was, and continues to be, “roots.”

“You’ve got your blues roots, r&b; roots, Cuban roots,” Lara says. “You’ve even got Rusted Root, which is some kind of root, I guess – I don’t mean that badly!”

Sunday’s performance features nine acts on two stages in a seven-hour bash: Cycomotogoat, Agents of Good Roots, Nil Lara, Taj Mahal and Son Volt on a second stage; 311, Rusted Root, Lenny Kravitz and Blues Traveler on the main stage.

Cycomotogoat is scheduled to open the show at 3:45 p.m. Blues Traveler is scheduled to close it, starting its set at 9:30 p.m.

More than music

In keeping stride with other festivals, HORDE boasts a variety of offstage diversions. A “Counter Culture Concourse” offers food, crafts, entertainment and politics a la carte. Veteran bluesman Taj Mahal will conduct guitar workshops at his self-styled “Alchemy Cabaret” – which sometimes morphs into an impromptu jam session with fellow HORDE musicians.

This year’s festival adopts a “Space Invasion” theme, with suitably spacey visuals decorating the venue. HORDE veterans may recall one of last year’s traveling attractions: “Whale Forest,” a 34-foot sculpture of a humpback whale hewn from a “naturally felled” redwood tree, with aquatic scenes carved into its surface.

The consciousness raising continues: This year, the Native American troupe Red Thunder will perform a five-minute dance on the main stage, following Rusted Root’s set.

Besides turning a profit now, HORDE, with its parent company, HORDE Corp., has also proved to be a personal triumph for Popper and his mates. Blues Traveler, a boogie band from New Jersey best known for Popper’s giddy, frenetic harmonica-play, is topping the HORDE bill while at the peak of its popularity.

The band has just released a live album, Live From the Fall, to follow up its quadruple-platinum smash, Four, which hit the Billboard Top 10 in 1995 and spawned the ubiquitous single and video, Runaround.

Blues Traveler also plays the closing credits on the summer movie, Kingpin, dressed as an Amish rock band, right down to the Pennsylvania Dutch rags and Popper’s slap-on beard.

That easy good humor seems to carry over to HORDE. Lara talks of the fun he’s had hanging out with fellow second-stagers like Me’shell NdegeOcello; standing backstage and watching King Crimson’s Tony Levin play amazing bass onstage; wowing musicians and tour technicians alike with his own exotic stringed instruments, the tres and the cuatro; and, of course, playing live.

“We just get onstage, give it our all, and go,” he says.

His only complaint? His set.

‘It’s pretty short, and they’re pretty strict,” Lara says. “When you hit 28 minutes, it’s like, wham! Time to go.”

But all in all, he doesn’t sound terribly bothered.

“This is a first and a blessing,” Lara says. “Out of all the bands that could do this – which is anybody – I get chosen.”