David Bowie, who has died of cancer a few days after turning 69, was a rock musician of rare originality and talent; he was also, variously, a producer, painter, film actor, art critic, the progenitor of bisexual chic, a family man and an astute multi-millionaire. Endlessly manipulating his public identity, Bowie was once rumoured to be an alien from outer space, and suggested in the mid-1970s tha