A listener's first experiences with the U.K. genre Grime can be jarring. Twitching 140 BPM drums and queasy synth shards snake beneath blasts of bulbous sub-bass. Emcees with nearly impenetrable Cockney accents unleash double-time raps that occasionally seem oblivious to the song's rhythm. It can be cacophonous and off-putting, but Grime also seethes with the sort of cultural and sonic vitality that has been missing from hip-hop over the past decade. Popularized on pirate radio, it is an outgrowth of U.K. Garage -- and though it still clings to that genre's A.D.D. beats, it lacks Garage's R&B flavor. Instead, Grime steals liberally from Jamaican dancehall and Southern hip-hop, and it is among the most exciting developments found in the music world this decade. Artists such as Dizzee Rascal, Lady Sovereign and Kano have made significant impacts upon U.K. audiences and have built up small but fiercely loyal fan bases in the States. As more artists begin to emerge from the East London streets, the genre continues to grow and flourish.