Kanye West

''Stronger'' started off intense, with West rapping furiously in front of a bank of erupting fluorescent flames — and the energy in the room only got, well, stronger when Daft Punk's glow-in-the-dark robots emerged from a massive pyramid to paw at their sampler pads. Still, West topped himself with the next number, ''Hey Mama'': a stripped-down strings arrangement and West's heartfelt delivery made the tribute to his late mother a real tearjerker. A