A guide to the year's defining pop sound.

Lil Scrappy/Trillville King of Crunk & BME Recordings Present: Lil Scrappy/Trillville (Warner Brothers) Click here to listen to "Head Bussa," and here to listen to "Some Cut."Hip-hop from Dixie has been ascendant for years, but a glance at the Billboard charts reveals that the lurching beats and bellowed choruses of Southern crunk have become 2004's defining pop sound. Etymologists will debate the derivation of the term for years to come—is crunk a combination of "crazy" and "drunk"? Southern slang for "cranked up"?—but there's no mistaking the genre's sonic blueprint: a pulverizing low end and lots of rowdy shouting, party music that mixes menace and pure mayhem. Crunk's self-proclaimed (and undisputed) king is Lil Jon, the Atlanta-based producer—and, after a fashion, rapper—who has a mouthful of diamond-crusted teeth, a scabrous voice, and now, his own pomegranate-flavored energy drink called (what else?) Crunk!!!. This joint release by two of his protégé rap acts is a good Lil Jon primer. With its stuttering keyboard line and what sounds like a choir of pirates roaring its title phrase, Lil Scrappy's "Head Bussa" is unadulterated crunk; but Trillville's sex ode "Some Cut" features Lil Jon's wittiest production touch: a backbeat built around a sample of creaking bedsprings.

Petey Pablo Still Writing in My Diary: 2^nd Entry (Jive)
Click here to listen to"Freek-A-Leek," and here to listen to "He Spoke To Me."Crunk began in the clubs of Atlanta as an experiment in streamlining, reducing hip-hop to its coarsest party-propelling elements: clobbering rhythm and a few hollered catch-phrases. Generally, it's hip-hop that has little room for expansive rappers. Petey Pablo's terrific new album features plenty of crunked-up sounds—listen to the telltale synthesizer arpeggios and background bellowing in the Lil Jon-produced hit "Freek-A-Leek"—but Pablo is an MC in the traditional mold, a fluent rhymer with grit in his voice and a lot on his mind. In fact, Pablo's traditionalism stretches back beyond hip-hop: In his Carolina drawl you hear echoes of James Brown, Joe Tex, and others who brought the exhortations and down-home homilies of the Southern church into black pop. On "He Spoke to Me," Pablo proclaims—and quite tunefully sings—his faith over a snippet of Al Green's "Love and Happiness."

8Ball & MJG Living Legends (Bad Boy) Click here to listen to "You Don't Want Drama," and here to listen to "Look at the Grillz."One telling sign that hip-hop's center of gravity was shifting southward was the emergence a few years back of 50 Cent, an archetypal New York MC who raps with a phony Dixieland twang—and brags about it. Now another New Yorker, P. Diddy, has followed the zeitgeist below the Mason-Dixon, signing Memphis rap veterans 8Ball & MJG as the flagship act of his Bad Boy South venture. Unfortunately, Diddy—who wouldn't be crunk even if you put him on a Crunk!!! energy drink IV drip—can't resist butting in; his dopey voiceovers ("It's Bad Boy South … yeah … unh," etc.) mar the otherwise sinister single "You Don't Want Drama," and his rapping on two other tracks is just silly. A far better North-South connection is made on "Look at the Grillz," when 8Ball & MJG are joined by Twista, the speed-demon MC from Chicago, who pours 16 bars of wildly syncopated rhymes over a woozy Lil Jon beat.

Lil' Flip"Game Over" (Sony) Click here to listen to "Game Over."A quartet for voice, keyboard, drum machine, and Pac-Man machine, in which rapper Lil' Flip complains about "producers who want to charge too much." That's odd, since "Game Over" is notable primarily for the ingenuity of its producer, Fury, who creates a strangely effective musical counterpoint using a five-note keyboard figure and the blipping sound of Pac-Man chomping those white pellets. Of course, it would be foolish to expect graciousness from the likes of Lil' Flip; it was his bravado that pushed him to the top of the heap in Houston and made him the ambassador for that city's sluggish, vaguely psychedelic signature sound. In "Game Over," Flip's boasts are banal ("My crib big like a football field"), but he's carried through by the sheer momentum of his bluster, by his distinctive slow flow, and by a choir of sycophants chanting, "Flip! Flip! Flip! Flip!"

Pitbull"Culo" (TVT) Click here to listen to "Culo."The debut single by Miami-based Cuban-American rapper Pitbull looks toward points further south. A joyous bilingual rap on a perennial theme—buttocks, and the uses to which they can be put, on dance floors and in bedrooms—"Culo" is built for optimum pan-demographic appeal. It's got party-happy Spanglish rhymes ("Ass and thighs like Trina and J. Lo … tiene tremendo CULO!"), Jamaican beatmaker "Scatta" Burrell's Coolie Dance Rhythm (heard elsewhere in hits by Nina Sky and Mr. Vegas), and, in a nod to the supremacy of crunk, raucous yelling by co-producer Lil Jon. It was the booming bass sound of late-'80s Miami hip-hop that laid the groundwork for crunk; the forthcoming albums by Pitbull and the sly female MC Jacki-O just might put their hometown back on the map. In the meantime, there's "Culo," with its delirious mix of voices: Pitbull and Lil Jon, speaking the patois of Little Havana and Atlanta; background chorus shout-outs to Dominicanas, Mexicanas, Columbianas, and "all my Haitians"; and a riddim straight out of Kingston, Jamaica—a festive cacophony of Southern accents.