Reggaeton is on a roll at the Forum

Anybody who’s never been to a reggaeton show -- and that’s just about everybody over 30 -- should imagine a cross between an arena rock concert, a raucous political convention and a high school pep rally, with a little sex thrown in for spice.

Imagine all that going full tilt for five hours and you get a good idea how 15,000 kids spent Friday night at the Forum in Inglewood, site of SoCal’s biggest reggaeton concert so far, the marathon Megaton 2005. The event featured a dozen acts performing the infectious Spanish hip-hop style that has become all the rage among urban Latino youth.

Some of the biggest names in the business topped the bill -- the cool and smooth Don Omar, the bawdy diva Ivy Queen and the gritty godfather of the Latin rap movement, Tego Calderon. Most of them hail from Puerto Rico, where the Afro-Latino style developed.

The rumor backstage was that some of the biggest egos in the business also jockeyed for position on the massive lineup. But except for the hapless opening act, L.A.’s Malverde, and the challenging closer, Calderon, position really didn’t matter. The audience was primed to cheer them all.

The quality of the act didn’t seem to matter, either. Some, like up-and-comer Voltio, sounded monotonous, which is not hard to do in this genre with its repetitive, computerized beats derived from Jamaican dancehall.

For a way-over-30 reviewer, the more droning sets allowed a break backstage where Spanish-language TV reporters eagerly interviewed performers, and provocatively dressed groupies tried to slink their way in. Back at the show 20 minutes later, it seemed like the same song was playing.

The better acts found ways to distinguish themselves through their flashy showmanship or their sound, mixing cumbia and bachata beats for a change of pace.

Or just by being outrageous.

After a riveting gangsta-style video, veteran Hector El Father came out tossing handfuls of cash to lucky fans in the front rows. John Eric, an extra-large figure draped in a baggy red coat, featured equally hefty female dancers in red tights who turned their ample derrieres to the audience with suggestive vibrations called “la lavadora,” the washing machine.

For those who didn’t get his message that big is beautiful too, Eric took off his shirt and showed off his rolls as he walked offstage.

Reggaeton’s back-up dancers add much needed visual excitement to a genre that, like rap, lacks real instruments and musicians onstage. Friday’s choreographed routines mimicked the music’s syncopated staccato beats in a cross between competitive cheerleading, high-impact aerobic exercises and a striptease.

The handsome Don Omar managed to come up with a new position for the music’s sexually suggestive explicit move, la perrea or doggie dance, when a particularly limber female dancer raised one leg in an eye-popping, upright split.

You’ll never see that as part of halftime entertainment at the Super Bowl.

Despite the raw sexuality, the mood of the crowd was somehow wholesome. People moved modestly to the grooves and sang along with almost every song, though many started leaving before Calderon’s 1 a.m. finish, perhaps too drained for his more socially conscious rap.

All night, fans cheered and waved flags as almost every artist ran through a roll call of nations, with Mexico representing the vast majority. Chants of “Latino power” underscored the appeal of this once-marginalized music with working-class immigrant kids. Just as with street salsa for their parents’ generation, they embrace it because it’s theirs.