With the arrival of Dizzee Rascal's "Showtime," British hip-hop is officially bounding through a very productive adolescence -- a period of creative fearlessness that recalls the '80s heyday of Def Jam Records. As with LL Cool J of that era, Dizzee's job is merely to be himself, at top volume, with no excuses.

"Showtime" features the same grimy panache that made Dizzee's debut, "Boy in Da Corner," more than a novelty. The 19-year-old East London rapper/producer (born Dylan Mills) lays Cockney-thick rhymes over wobbly, skeletal beats, forcing hip-hop's American DNA to meld with the robotic noise of Britain's underground club culture. Somehow, none of it sounds like a prank.

Where "Boy in Da Corner" was a journey into the dark side of Dizzee's psyche, "Showtime" is a loud examination of his success, which includes Britain's Mercury Prize and a nomination for America's hipster Shortlist Prize. But his ego is moderate by hip-hop standards. The disc's first single, "Stand Up Tall," is more playful than aggressive, and its message -- that ghetto kids must seize the moment -- sounds born of love, not utter frustration.

The song's groove is its real triumph, though: Speedy, light and insanely catchy, it has the charm of a Super Nintendo game soundtrack without pandering to consumer-tech nostalgia. But much of "Showtime" follows in the heavier sonic footsteps of "Boy in Da Corner." The pots-and-pans percussion and dry bass line of "Everywhere" sound as if they could collapse at any moment, as Dizzee addresses the haters: "Yeah, I'm way beyond care / Hate me or love me / Try not to stare."

Likewise, tracks such as "Hype Talk" and "Knock, Knock" push against pop conventions like a firecracker in a mailbox. And things do get a little meaner as the disc progresses, hitting a peak at "Respect Me," where Dizzee delivers a woozy late-night beat and plenty of clenched-teeth warnings about how "you people are gonna respect me if it kills you."

Just when he seems ready to succumb to his darkest impulses, though, Dizzee offers balance and detachment. The measured "Get By" follows "Respect Me" with an Asian-flavored keyboard motif and an objective analysis of life on Britain's council estates. "If you know you're from the slums, keep reppin' no doubt / Stay ghetto if you must, just remember to get out," he says, again assuming the well-worn role of cheerleader for the downtrodden.

Moments like that are when Dizzee's repertoire seems most American, even if the backing groove has the vibe of an abstract space opera. That's because hip-hop's greatest motivators are hunger and boredom -- it's the same in the Bronx as it is in Dizzee's neighborhood of Bow. He's still hungry in a teenage way, and that's probably why "Showtime" sounds more like the fitting sequel to "Boy in Da Corner" than a purposefully new direction. In the end, the important thing is that Dizzee (along with the Streets' Mike Skinner) appears fully capable of shepherding his country's hip-hop into a flourishing adulthood.

"Showtime," from East London rapper Dizzee Rascal, lays Cockney-thick rhymes over wobbly, skeletal beats.