M.I.A. wasn’t always known primarily as a culture-hacking, sociopolitical lightning rod. Her wildly inventive, musically polyglot 2005 debut, “Arular,’’ highlighted her agitprop worldview, but it was couched in such a conspiratorial blend of world music that the politics were merely in cahoots with its dance directive. After the worldwide apoplexy over “Paper Planes’’ in 2007, M.I.A. seemed to have sobered up her game. Signing on as the global icon for the politics of oppression can’t be much fun, pastel fashion sense notwithstanding. It’s no surprise then that her music isn’t much fun anymore. Here a team of producers have distilled her stridency into a willfully defiant blast zone of discordant electro hip-hop. “Steppin Up’’ is one example, with its looping power tool rhythm and bomb whistle effects; “Born Free’’ is another — thrashy, lo-fi synthpunk that antagonizes with its artful dishevelment. Mercifully, “It Takes a Muscle’’ is a grooving dancehall romance, while “Teqkilla’’ utilizes M.I.A.’s trademark playfully-menacing sing-song flow. But like “XXXO,’’ which leavens the clamoring production racket with a captivating hook, it’s dirtied up with song-obscuring noise. (Out tomorrow).