The six 25-minute films seen here, each about a famous tenor whose recordings were made on 78s, were part of a German television series in the mid-1990s. They contain a wealth of visual material, with commentaries by people who for the most part have something interesting to say. The singer’s voice is plentifully interesting, with character and life story that become vivid as perhaps never before.

For each, the producers have managed to find people with a personal connection. In the Caruso film, a lively old New Yorker remembers as a boy being called down to dinner to make a 14th, Caruso being one of the guests and utterly refusing to sit down at a table of 13. Of Gigli, everybody remembers something special – Simionato his use of portamento, Adami-Corradetti his generally being ‘no actor’ but nevertheless terrifying her in Act 2 of Pagliacci when she played Nedda to his Canio. Of Schipa we learn that he carried with him such a sense of presence that you knew if he was in a room even if you couldn’t see him.

Some famous old faces appear momentarily – Elisabeth Bergner telling how she took a hearty dislike to Tauber when she saw him in Lehár but was completely won over when he sang Mozart. And a group sitting out of doors round a table piled high recall how Slezak enjoyed his food, which he ate ‘with passion’. They demonstrate.

With Joseph Schmidt, the last of them, it was evidently harder to find survivors from the grim years which brought him to such a sad end – he died in an internment camp during the war – but they make up for it in the commentary from London cantor and voice-expert Alan Bilgora, writer Jürgen Kesting and Stephan Zucker.

It’s a pity that commentary and film don’t coincide more often (the one distracting from or failing to explain the other). Often a specific point is made about the singing and not immediately (as it could have been) illustrated on record. And of course there’s some awful rubbish, musical and dramatic – so much so that many would say those words don’t really apply. But there’s no boredom: no moment when (let’s say) you can wander off into the kitchen with the assurance ‘I shan’t be missing much’. You have to watch.