“I’m an instant star,” David Bowie once quipped, “Just add water.” In truth, did any other artist of the 1970s have such an impeccable run of essential, trend-setting albums? Finally finding fame with his Martian rock messiah following several years of creative taste testing from novelty jingles about laughing gnomes to dabbles with folk trio Feathers, by the time he was slinging his arm around guitarist Mick Ronson’s shoulder on Top of the Pops…