Ryuichi Sakamoto was not a man cut out to be a pop star. As a teenager, he liked the Beatles and the Rolling Stones, but his abiding passion was New York’s underground avant garde art scene – Joseph Beuys, Fluxus, Andy Warhol – and its accompanying experimental music: he was fond of pointing out to interviewers that he was born the year that John Cage composed 4’33. At university, he studied the work of modern composers Boulez, Stockhausen and Ligeti; he had a particular interest in the challenging electronic compositions of Iannis Xenakis. The first album to bear Sakamoto’s name, 1975’s Disappointment/Hateruma, was a collaboration with percussionist Toshiyuki Tsuchitori that consisted entirely of free improv. If he was going to have a role in the Japanese pop world at all, it was in the background, using his keyboard skills and interest in the fast-developing world of synthesisers to find employment as a session musician.