The six-film collaboration between Karajan and French director Henri-Georges Clouzot in 1965-67 changed the way orchestral music was filmed for television. Glenn Gould, who relished the pair’s “affront to the conventions of the concert hall”, particularly admired the Dvorák. It is indeed an electrifying performance by a rejuvenated Berlin Philharmonic at the peak of its powers; it is also a visually stunning record of a masterclass in virtuoso conducting.

The Mozart film was the first to be made and is the least characteristic, since Clouzot chose to shoot it not in a virtual studio space but in a candles-and-mirrors rococo salon. Mirrors suggest narcissism and there is something of that here. When Menuhin was re-shown the film during the making of a Bruno Monsaingeon documentary, he expressed amusement at Karajan’s affected demeanour, comparing his old friend to one of the beautiful Lipizzaner stallions in Vienna’s Spanish Riding school. Of the six films, this was the one Karajan least liked.

The bonuses are interesting. There is a previously unseen sequence in which Karajan rehearses the strings (in English for some unexplained reason) in the opening of the Mozart’s slow movement. There is also a filmed conversation between Menuhin and Karajan, the first part of which is embarrassingly stilted and mannered as Karajan, in faltering English, attempts to explore with a somewhat sycophantic Menuhin the relationship between sound and silence in the musician’s age-old search for continuity of phrase (when Gould worked with Menuhin he scripted the conversation!). There are, however, nuggets to be mined, making this a useful addendum to the now legendary rehearsal film of Schumann’s Fourth Symphony which Clouzot made with Karajan.

The German-language conversation with Joachim Kaiser about folk elements in the New World Symphony is a tour de force. This high-speed, high-octane conversation (and it really is a conversation) about the interface between folk music and the symphony ranges far beyond Dvorák, with a fascinating array of musical, historical and wider cultural references thrown in by both parties. People often ask what Karajan was like to talk to. Here is the answer.