MOTHER TONGUE.

Despite having invented the English language and those clever TV shows, Britain hasn't withstood our cultural colonization any better than the rest of the world. In the eighties and nineties, British m.c.s generally sounded like variants of their American counterparts. Having an adorable accent didn't disguise the fact that you'd borrowed your style from Rakim, or Run-DMC, or Nas. The debt is finally being erased. The music coming out of Birmingham and London today sounds nothing like American hip-hop. You can't even call it hip-hop--though it wouldn't exist without hip-hop.

Two very different ambassadors of this moment are Mike Skinner, a.k.a. the Streets, a twenty-five-year-old white man from Birmingham who specializes in shaggy-dog stories, and Dylan Mills, a.k.a. Dizzee Rascal, a nineteen-year-old black man from East London who uses his remarkable voice to punch holes in the air. Mills won the corporate-sponsored Mercury Prize last year for his album "Boy in Da Corner," and Skinner's new record, "A Grand Don't Come for Free," is favored for the same prize this year. Earlier in the summer, the two appeared together here, at Irving Plaza.

The club filled early--Skinner and Mills have sturdy followings--and Mills appeared first, performing with a hype man (someone who exhorts the crowd and sings along with key lines) and a disk jockey. Wearing a Yankees cap, Mills was calm and businesslike. He is small of stature but moves with equilibrium and carefully parcelled-out effort, as if he'd known since kindergarten that people are watching him. He raps over music that he produces himself; the consensus term for this genre is "grime," though the sounds are paradoxically clean in the way that only digital media are clean. Some grime tracks sound like buzzers rasping inside an oil barrel; others seem to have been made from cell-phone ring tones. The music is synthetic and hits hard, almost to the point of punishment. What strikes an American ear is the rhythm. Even the most aggressive American hip-hop is indebted to the African-American musical tradition of emphasized downbeats and swing. These tendencies are human-friendly even when the lyrics aren't. Grime shares neither this lineage nor these concerns. Its roots are in the fast and furious fusion of Jamaican dance hall and English rave music called drum and bass, and another, lighter dance music called garage. (No relation to garage rock.) If you're bracing for a test, there are two major points: grime's first motherland is likely Jamaica or England, rather than America; and grime favors fast, anxious tempos that rarely show up in American hip-hop. Grime smacks and bullies whatever time signature it is grudgingly participating in. Mills's best tracks, such as "I Luv U" and "Stop Dat," are like arguments between two implacable robot telemarketers. If popular music is how each young generation establishes its voice and draws borders with surrounding generations, grime has done it in a fairly logical way. Adults are just organic, fallible, dishonest creatures. Hard drives and cell phones are always there.

Working with his own music at Irving Plaza, Mills was relentless. When he started rhyming over the instrumental of the American hip-hop hit "Tipsy," he outclassed the song's original performer, J-Kwon, in a handful of verses. His most flattering collaborator, though, was silence. Several times, his d.j. stopped playing records and Mills rhymed a cappella. His accent is strong and his voice slightly stopped up, as if there were no easy way for him to say anything. But Mills can say just about anything, and more nimbly than your average human (or machine). As he built up his oration, angle by angle, the crowd followed along, cheering so generously that it was somewhat disappointing when plain old music returned. On his new album, "Showtime," due in September, Mills reduces the musical aggression to make room for his increasingly virtuosic rapping. There's ...