Within seven minutes of BBC1 picking up live coverage, Chris Rock gets in the first "C’mon motherfuckers". This shortly after David Gray and Damien Rice have murdered "Que Sera Sera", Snow Patrol have yelled, "Looking forward to Spinal Tap? We are!" and Geri Halliwell has walked onstage to say, "Isn‘t it great my band are back together?" While the eight concerts around the world constitute an immense, well-intended event, the Wembley show is a thoroughly surreal mish-mash of deafening hard rock, weightless aerobic pop and celebs spouting platitudes.