The ascendance of Lil Jon has to be among the strangest in a pop-music world where strange ascendance is a matter of course. He was a regional hip-hop figure who became famous, basically, for yelling a lot. His every move qualifies as a spectacle -- a frenzied mess of stringy hair and glinting gold teeth. In the classrooms of hip-hop, Lil Jon reigns as the king of the style known as crunk; in the playground of pop, he is a sort of cartoonishly malevolent clown.

What made Lil Jon huge was "Yeah!," the single he produced for the otherwise lackluster R&B star Usher. Lil Jon was already big for his own rap hit "Get Low" -- but not huge enough to cause an outbreak of awkward dancing at wedding parties and office functions across the land. Throw in a timely impression by the comedian Dave Chappelle, and Lil Jon was the kind of pop star whom any unwitting American with her eyes open might be surprised to realize she knows.

Lil Jon's music is much darker and more manic than "Yeah!," though. On his own, the Atlanta native epitomizes the Dirty South at its dirtiest. And its scariest, too. Those would be the catchwords for crunk, a movement that gets drunk on beats that sound crooked, cracked and crunchy. Take the first real song on Lil Jon & the East Side Boyz' new album "Crunk Juice": Under a chorus of rappers barking grave orders to "Get Crunk," the beat stomps like soldiers marching over a bridge groaning under their weight. Horror-movie strings add to the aura of doom, but Lil Jon and his comrades would sound just as ominous with no music at all.

A later track on the album samples not one but two songs by Slayer -- cementing crunk's role as the hip-hop equivalent of death metal. The bulk of "Crunk Juice" traffics in outrageous revenge fantasies and statements of bloody intent. (One song threatens enemies as well as their wives and children.) There's really nothing else happening in the lyrics, whose carnival of violence and misogyny teems over macabre music made to match. "Da Blow" skulks with the kind of slow, woozy menace favored by recreational drinkers of cough syrup, while "White Meat" gets by on a junky diet of bass and minor-key synthesizer patterns.

Lil Jon is best at this most sonically nihilistic, when his sense of cinema serves scenes that rise out of the din. Otherwise, he's left to phone in chart bait like "Lovers and Friends" and "In Da Club," a sex ballad and a would-be dance track on which Usher and R. Kelly sound listless and lame, respectively. It's striking how unnatural Lil Jon sounds when he's not screaming bloody murder over murderous beats; without a hater to brace against, he has nothing to say and nothing to play while he's saying it.

Lil Jon and the East Side Boyz, serving up a poisonous cocktail of misogyny and revenge fantasies.