Are shaggy hipster bands really starving Lower East Side garage rats? Do pretty girls still validate emo punks by ditching them for the star football hunks? Are the bling and swagger of hip-hop heroes mere artifice? Nobody knows for certain. But I do know that 19-year-old British rapper Dizzee Rascal's debut album, Boy in da Corner, thrives solely on its authenticity. The menacing atmosphere of his east London stomping grounds seeps into Corner's creeping two-step pizzicatos ("2 Far"), ominous string samples ("Stop Dat," "I Luv U"), shadowy bass blurts ("Cut 'Em Off") and sirens-and-gunshots sound effects ("Sittin' Here"). England's musical diversity informs the album's stutters and flutters, from "Seems 2 Be," a nimble cut-up of Basement Jaxx's early syncopated insanity, to the brilliant braggadocio of "Fix Up, Look Sharp." But what's truly genuine -- and nearly inimitable -- about Rascal is his wordplay. His songs stand alone as gritty poems with an intuitive grasp of meter, rhythm and rhyme. Whether firing a cautionary tale involving teenage troublemakers on "Jezebel" or lamenting life in the 'hood on "Here," Rascal spews turns of phrase in a jittery brogue wired with rough grace and even rawer visions of reality.