Alone in the big box, he was also terrified by the Grand Inquisitor, blind, hooded, bent over his sticks like a black widow spider, and when the flames began to flicker round the poor bare feet of the heretics, Tristan leapt to his own feet screaming, ‘No, no they mustn’t burn,’ which was luckily drowned, by orchestra, church bells and chorus loudly praising God and the Inquisition.

Every role in Don Carlos is demanding, but it was the young Hermione who drew the most rapturous applause. Tristan clapped his hands until they were as pink as the carnations that cascaded down on her.

After more champagne and hugging, as people poured backstage to congratulate them, Rannaldini, Cecilia, Fat Franco, who’d sung Carlos, and Hermione swept Tristan off to the Ritz, where he still couldn’t speak for excitement. Everyone was sweet to him because Rannaldini made sure they knew both of his birthday and of his famous father.

The management presented him with a frothy fruit cocktail filled with coloured straws. Rannaldini, who never minded what the boy ate, allowed him to have lobster Thermidor with sizzling cheese topping, followed by blackcurrant sorbet.

Hermione, who’d changed into low-cut dark blue lace, presented him with one of her pink carnations. Then a birthday cake arrived with ten candles and he opened Rannaldini’s presents: a red leatherbound copy of Schiller’s play Don Carlos on which Verdi had based his opera, and a video camera. Tristan couldn’t stop saying thank you.

‘He already play cello very well,’ boasted Rannaldini.

‘Are you going to be a musician?’ asked Hermione.