Which of these three great conductors said this: ‘My intention always has been to arrive at human contact without enforcing authority…The great mystery of music-making requires real friendship among those who work together…’? As sure as hell it wasn’t Evgeny Mravinsky (1903-88). In a head-to-head for Most Frightening Conductor, he would beat Fritz Reiner by a scowl. Unsmiling and austere, he is the thin-lipped, sadistic headmaster of your nightmares.

From the likes of Kurt Sanderling and Mariss Jansons we learn in the course of this thoughtful, rounded and well-paced portrait that the looks mirrored the personality. Even his widow, the third Mrs Mravinsky, complains of his meanness. If not loved, though, he was revered and the film, with its generous rehearsal and performance footage, of how this miserable Russian aristocrat in a cardigan survived the Soviet regime and remained conductor of the Leningrad Philharmonic for nearly 50 years despite his disdain for the Party, is fascinating.

If the documentary does not entice you, then the misleadingly entitled ‘bonus’ surely will, one of the most deeply expressive and thrilling performances of Tchaikovsky’s Fourth Symphony I have ever experienced: Mravinsky’s orchestra at the 1971 Proms under the genial baton of Rozhdestvensky.

Another aristocratic-born Russian conductor was Igor Markevitch (1912-83). I cannot recall ever seeing him ‘in the flesh’ before – concise, elegant and refined in the Rossini and Beethoven (he finds a beguiling pulse in the finale of the Pastoral), even if ultimately he fails to engage the emotions. This is due in part to the sound (very mono indeed) and the dry studio acoustic that takes the bloom off phrase endings. The chief casualty is Seefried and her uncertain intonation in three Mozart arias; Maureen Forrester fares better in her heartfelt Brahms. The camera does not dwell exclusively on Markevitch, perhaps because he has only one facial expression: blank.

So to the source of the opening quote, Carlo Maria Giulini, now living in seclusion in Milan. From the first few moments of the rehearsal, you know that he practises what he preaches, a gracious, spiritual presence whose stature does not preclude him from apologising at one point to the solo French horn for suggesting a misleading dynamic: ‘Sorry, that is my mistake – it sounds too much like Debussy’. If, like me, you are unfamiliar with Bruckner’s Ninth (the one he left incomplete at his death), then this absorbing hour-long sequence will prove a stimulating, unmissable introduction; for aspiring conductors and Brucknerphiles, I would rate this and the live concert performance as an essential purchase for repeated viewing.