Music is a cyclical medium, what goes around comes around. Each 'generation' wants its own version of the sounds that form the core of rock and pop - metal, punk, r'n'b, and, at the moment - American New Wave. So, Black Sabbath were great, but the next time around, they were Metallica, and the next time, Slipknot. Television were fantastic, now they're The Strokes. The Ramones are timeless, so The White Stripes borrowed their buzz, and so it goes on. As to whether they are any good or not, is a matter for the individual listener to decide, but one sure fact about any aspect of culture is that cream does rise to the top. Time will tell if any of these bands have got staying power, but stars that explode and burn brightly have their own appeal, as do comets that blaze for ever. This does not include Pop Idol contestants who are exempt from any of the above criteria.