Wonderful world, beautiful people of reggae live on BY SANDRA BARRERA Los Angeles Daily News Ben Harper was headlining a blues festival in Ottawa on a recent Friday when he broke into a medley, pairing his new My Own Two Hands single with the Bob Marley tune War. As if on cue, the audience of 21,000 began to sing along word for word, note for note. But it wasn't Harper's song they knew by heart. It was that of Marley, who remains a deity in the world of reggae and a continuing influence on the music scene. The scene thrilled Roger Steffens, an L.A.-based musicologist who specializes in reggae. ''It was the kind of response I used to see Bob [Marley] get when he was alive,'' Steffens says, ``and it was kind of nice to see a new generation reacting that way to one of their own.'' Harper, 33, is by no means a reggae artist. But like reggae, his music calls for social and political change in cadences that are at home at frat parties and folk concerts alike. Like many other contemporary alternative artists, he is carrying the torch of Jamaican music and evolving it. NOT FADING AWAY From other like-minded musicians to crossover dancehall sensations to roots purists, the voice of reggae continues to be heard across a landscape that persistently throbs with hip-hop, pop and the sexy-babe-du-jour. The irony is that even those babes -- like the bootylicious Beyoncé -- have found inspiration in the more self-consciously political music that emerged from the shanty towns of the Caribbean. Reggae, it seems, is here to stay. Wailing Souls' Lloyd ''Bread'' McDonald says it's the ''great rhythms, great lyrics'' and that ``people can dance to it . . . that make this music popular.'' Reggae festivals, such as the one Aug. 24 at the Hollywood Bowl featuring the legendary Jimmy Cliff (who plays South Florida Aug. 17 at Miami's James L. Knight Center), and concerts are the rain forests of the music ecosystem. They thrive on diversity, bringing together different generations, complexions, fashions -- even political points of view. Which is not unlike the appeal of reggae-inspired Harper and his band, the Innocent Criminals. In fact, Harper took part in the recent sold-out Reggae on the River festival in Northern California before resuming his current tour with Jack Johnson, an erstwhile pro surfer who weaves acoustic reggae, blues and rock into something breezy and wholly his own. Both artists have been slipping a Trenchtown anthem or two into their separate sets. Johnson has even joined Harper for an encore performance of Bob Marley's High Tide or Low Tide. Johnson says he used to do covers because he needed the material since he didn't have much of his own. That's not true anymore, but he still likes to throw some snatches of reggae, and even punk rock, into the mix. ''It's still kind of fun to drop in different covers of music that you've been listening to or just little things we start messing around with at sound check,'' he says. When Julian Marley encounters the overflowing river of love and respect for his father's artistry, he gets a little overwhelmed. ''It's beyond what we can explain. It's godly,'' he says. WHAT ABOUT BOB? For many, Bob Marley remains the great reggae artist; that includes Steffens, who got to know Marley before his death in 1981. Steffens was hosting a radio show on L.A.'s KCRW-FM when he spent two weeks on the road with the native of rural St. Ann's Parish, Jamaica, describing him as ``disciplined, generous to a fault, personable, quiet, masterful, a leader, charismatic.'' In their pure form, Marley's songs are already classics, and his albums to this day account for more than half of all reggae music sold in America, Steffens says. But Marley's children try to evolve the reggae vibe in their own ways, having branched out into areas of rap, pop and R&B. Julian Marley's forthcoming album, due later this year, fuses classic R&B with jazz and salsa. His brother Ziggy's solo album away from his famous group, the Melody Makers, is a mix between pop and rock. Elsewhere in the mainstream, reggae's influence has also made a splash, thanks to the dancehall sensation Sean Paul, whose platinum-selling Dutty Rock, which incorporates hip-hop slang, has generated radio-friendly singles. Wayne Wonder, another dancehall crossover, has found a niche on the airwaves melding reggae with R&B. But in the commercial success of both Wonder and Paul, the message has been lost, reggae purists contend. In reggae, the message is everything. ''When Bob Marley talks about chasing those crazy baldheads out of town, it's the same thing going on in Africa right now,'' says David Hinds, whose British reggae group, Steel Pulse, also has taken the oppressors of the world to task. It's a message that resonates strongly with fans, who on a recent Saturday night packed L.A.'s Roxy to see Steel Pulse in action. Not a voice in the wall-to-wall, ethnically diverse crowd of sweating, dancing revelers was silent. ''There's times when I don't see any point in singing because the monitors are ineffective,'' Hinds says. ``People are drowning me out, they've taken over. It's a good feeling.'' The music was built on the foundation of the Rastafarian faith, which among other things preaches peace, justice, equal rights and the divinity of Ethiopian emperor Haile Selassie. At least the first three are themes that recur in every generation of reggae artists and those who would be like them. For Steffens, Harper is an example. ''I think he's a brilliant artist, I really do, and not just because he filmed his new video in my house,'' Steffens says, chuckling. JIMMY CLIFF IN CONCERT Jimmy Cliff appears with Floetry at 7 p.m. Aug. 17 at the James L. Knight Center, 400 SE Second Ave., Miami. Tickets are $41.50-$51.50 and available at Ticketmaster. Call 305-358-5885 (Miami-Dade), 954-523-3309 (Broward) and 561-966-3309 (Palm Beach).