The 90-minute film of One11 was the major project of Cage’s final years and was completed just three months before his death in 1992. When asked why he took on something new in the medium of film, Cage said he jumped at the opportunity because there wasn’t much time left. Sadly he was right.

The music is a seamless garment of continuous sustained sounds, with some individual notes picked out, in the style of Cage’s late “number” pieces. There’s a choice of two soundtracks that are independent, of course, from the visual images but nevertheless uncannily appropriate. Cage said the film has “no plot, no characters, nothing”, hoping it would “give pleasure without having any meaning whatsoever”. He wanted it to be “free of politics, economics and even of oneself”. The documentary material with the DVD shows that the film was elaborate to make: there are 17 scenes requiring 1,200 cues with 20 light-changes each – all indicated in charts for the technicians derived from Cage’s usual chance methods. The camera is the soloist.

These details don’t explain the remarkable quality of these uniquely pure visual images, studies in light ranging from total black to total white. No colours. The play of lights brings up slowly moving circular objects eerily reminiscent of distant moons transmitted from outer space posing the eternal questions of existence. At times the scenario suggests cloud formations viewed from a plane. Cage’s formulae for removing personal taste have paradoxically produced mesmeric images that only he could have devised.

Cage himself is interviewed but understandably seems tired compared with the sparkle of his younger self. But what a splendid project carried out with dedication by all concerned.