Here are two albums released on the same day, and both by artists taking shelter in the broad church of hip-hop. There the similarity ends.

The seventh studio set by Philadelphia's The Roots is dark and brooding, tackling issues such as the war in Iraq, government surveillance, urban decay and poverty.

MC Black Thought's rapping is tight, controlled and interesting - as is the backing. You get an idea of the kind of cross-fertilisation that's going on in the minds of The Roots on Atonement. Suddenly it becomes clear that the track is based on Radiohead's You And Whose Army.

This is not a reference you are likely to find on Ice Cube's new album. The granddaddy of original gangsta-rap has returned from a six-year absence for Laugh Now, Cry Later. A lot has changed since his early days with renegade rappers NWA.

Ice is no longer considered armed and dangerous by white middle-America. On the contrary, he is now the hilarious star of a series of lightweight ghetto comedies.

But when it comes to the music, Ice has stuck to his previously successful formula - rapping about gangstas, guns, bitches and blow, over chilled out, bass-heavy backing, a la Snoop or 2Pac.

Yes, it is a clich-ridden wasteland, but then again, he is rapping about LA. In contrast, Game Theory stays true to its strategic name, and delivers a bit more nuance.