Musicians evolve at the risk of losing their audience -- fans always prefer known quantities to variables. David Bowie is one performer who's made a career out of defying rock convention so flagrantly and with such finesse that fans not only forgive him for it, they worship him. From the fey folk of his pre-Space Oddity days to the right-angled, martinet funk of "Fashion" and Tin Machine's bloated Hard Rock, Bowie's only constant has been his inconstancy. Considering his vast...  [+]