That “coda” in the title is maybe more wintry than it need have been. The Japanese film composer, musician and anti-nuclear campaigner Ryuichi Sakamoto was diagnosed with cancer in 2014, and his prodigious work rate had to slow to a virtual standstill. Stephen Schible’s documentary portrait follows the musician in the calm and introspective period forced on him – but it also shows him participating in post-Fukushima demonstrations. But whatever he had feared, and prepared himself for, this cancer is now in remission and so far it has not come back.

Sakamoto made his breakthrough writing the music for Nagisa Oshima’s Merry Christmas, Mr Lawrence – one of the most famous movie themes of the 80s with its inspirationally catchy westernised pop take on Japanese music. He also wrote for Bertolucci’s The Last Emperor and the same director’s The Sheltering Sky; later we see him attempting to compose a musical accompaniment to author Paul Bowles’ cameo-soliloquy in that film. His career continues unabated to the present day, and he wrote the score for Iñárritu’s The Revenant.

As a young man in the 80s, he looked like a new romantic pop star; now he is an elegant grey-haired mandarin, who could be a celebrated designer or award-winning architect. He is very interesting on Tarkovsky’s use of Bach chorales in his 1972 sci-fi classic Solaris and is shown thoughtfully working on some chorale-type compositions of his own. He is also ceaselessly interested in the possibilities of electronic music, though I have to say shots of him at the piano keyboard are more interesting than him at the computer keyboard.