It's tempting to link the revival of politically engaged hip-hop to the rise of Barack Obama but the real reason lies elsewhere - in the Bush administration's lack of concern for black victims of Hurricane Katrina. Since then, scarcely a rap concert goes by without unquotable references to George W. Bush, as at Jay-Z's set at the Glastonbury festival last weekend, while an appetite for "responsible" hip-hop has propelled consciousness-raising rappers such as Common and Talib Kweli to the top of the US charts.

Into this climate steps Erykah Badu with her startling album New Amerykah, Part One (4th World War) , a dark portrait of American race relations drawn in the far-out style of Sly Stone or George Clinton. An inspired return to action after a period of writer's block, its entrancing songs are a far cry from the 37-year-old singer's roots singing hippyish retro-soul in flowing earth-mother outfits.