The battle stages are now over, and Paloma Faith, Boy George, Will.i.am and Ricky Wilson each now have a complete team of would-be stars under their tutelage. The next challenge the contestants face is the knock-outs, in which they must carefully sel... (more)ect and perform a 'killer song' that will elevate them above their team rivals, as the coaches whittle their eight chosen singers down to three.