It is like watching childbirth. Through a narrow channel (the movie projector beam), with struggle, exertion and sometimes pain, a living entity (the opera film) is forced out into the world. The first impression is of a bawling mouth and lots of noise. The first instinct, often, is to hold the creature upside down and smack it hard.

But the end result can be a miracle: a living organism growing up straight, rich, true and complex. Though the infant mortality rate in filmed opera is high – famed fiascos include 1953’s Aida with Sophia Loren miming to Renata Tebaldi’s voice – we can think in compensation of Syberberg’s Parsifal, Losey’s Don Giovanni, Bergman’s The Magic Flute. Next week we have the UK release of Kenneth Branagh’s The Magic Flute: very different from Bergman’s, possibly a candidate for smacking, but with moments of giddy grandeur.