Most of what you find in the world-music section tends toward the gentle, melodious, and uplifting, as if the world were that way. The music of Maya Arulpragasam, a twenty-seven-year-old Sri Lankan Tamil who moved to England when she was nine and performs under the name M.I.A., is not like that. Anyone who has trolled through bins for videos of kung-fu movies or reggae mix tapes will recognize M.I.A.’s first single, “Galang,” as an example of actual, on-the-ground world culture: synthetic, cheap, colorful, staticky with power. It most resembles Jamaican dancehall patterns, but with a twist. Alongside the beat runs a distressed motif that may have been a melody before it was Xeroxed fifteen times. The lyrics combine the exhortations of dancehall, the embattled war mentality of American hip-hop, and a scenario that sounds far removed from her London home.