This week Hänsel und Gretel returns to Glyndebourne.  Boasting a dizzying array of confectionary,  the requisite child-eating crone and, of course,  a singing and dancing children’s chorus, Laurent Pelly’s 2008 staging speaks to the kid in all of us. And it has me thinking about that unique cocktail: children and opera.

Of course, it’s hardly an untapped resource. What would Britten, for example, have done without the voices of children raised in song? The Turn of the Screw would have been rather compromised; Noyes Fludde would simply not have happened. But with few singers entering the opera profession before their twenties, what is it like, I wonder, to make your opera debut while still at school?

I put this question to Janette Heffernan, a producer living in New Zealand. She is well-qualified to answer: she was handpicked by Britten to play Flora in Peter Morley’s 1959 television production of Turn of the Screw at the age of 15. “It was quite scary”, she says. “In those days you couldn’t cut the tape, so any mistakes we made were there forever.”

Heffernan was a young ballet dancer when she met Britten. She danced in a Royal Ballet production of Petrushka alongside Margot Fonteyn before landing the part of Mrs Sem in Britten’s children’s opera Noyes Fludde. It was while playing this role that Britten selected her for The Turn of the Screw. He had previously seen about 40 potential Floras, but something about Heffernan - née Janette Miller - stood out. “The thing about Flora is that she is an adult in a child’s body and I was old beyond my years,” Heffernan says. But she admits that the part was difficult. It was, after all, written for an adult soprano. One person who helped her was the recently, and sadly departed Sir Charles Mackerras, who conducted the television performance. “He was very understanding,” says Heffernan, “he knew it was difficult for me and that I was new to it all. At the dress rehearsal he allowed me to do my aria twice so that I could get the hang of it.”

While playing the role she struck up a friendship with Britten. She would go to his flat in St John’s Wood in London and sing lieder with him. “We would talk for hours about Mahler, motorcars, and the part of Flora. He told me I had her just right and that I shouldn’t change a thing.” They also went for drives together: “I was always asking him to let me drive, but he never would.” She continued to exchange Christmas cards with him for several years afterwards.

Heffernan gave up opera singing in her adulthood and moved to New Zealand. Once there she founded her own opera and ballet company - something she attributes to a childhood spent performing. “I could never have done all this had I not had the experiences I had as a child.”

Whether the children of the current Hänsel und Gretel production will one day make the same claim remains to be seen. But although Engelbert Humperdinck may not be around to hand-pick and train the cast of his opera himself, the Glyndebourne team seem to have managed well by themselves: Pelly’s production boasts a strong team of 11-14 year-old boys and girls, courtesy of Croydon’s Trinity School for Boys and Ashdown House School in Easy Sussex. The children are in good company with mezzo-soprano Alice Coote as Hänsel, and the German soprano Lydia Teuscher, who makes her UK debut, as Gretel.

I arrive at Glyndebourne at a critical moment: the witch has just been locked in the oven and the chorus prepares to unite in a celebratory extravaganza. The conductor Robin Ticciati is getting his teeth into the score, and his boisterous energy is infecting the children. Or perhaps it’s the other way round?  One small girl detaches herself from the rest of the group and hops wildly from one leg to the other. As the music gears up for the climactic refrain, they all join hands and skip across the stage. I note that one side of the chain seems to be made up of boys, the other, of girls.

“They’re at that funny age when boys want to be with boys and girls with girls,” says Stéphane Marlot, the revival’s director. “They’re becoming more self-aware.”

I’m granted an audience with three of the children. Ben (14), Leo (13) and Joe (11) solemnly shake my hand before arranging themselves in a line for questioning.  I ask them if they’re enjoying the rehearsals. They nod. “We get to wear fat-suits,” Ben elaborates. He is referring to their bulbous attire - an apt demonstration of the witch’s ploy to fatten up her victims.

By now both Ben and Leo are opera veterans: they were involved in the same production when it was first staged in 2008. Although not a specialist music school per se, Trinity has been preparing boys for opera choruses for over 40 years.  “Boys who come back for revival productions often find costumes with a fellow pupil’s name in it from a previous year.  Then they come back to school and say, ‘I’ve got your costume!’” says their chaperone David Swinson.

Trinity offers a large number of boys sponsored singing lessons.  The earnings made from their professional opera work are then fed back into their singing training, and so the cycle continues. For many of the pupils, including Joe and Leo, these lessons provide their first foray into singing. “I had never sung before I came to this school. Then I did one singing test and that’s what got me into it,” says Joe.

Swinson chooses boys whom he considers suitable for the opera choruses, and then prepares them for the productions as part of their schooling. “A lot of children’s roles in operas involve singing a single line in unison but in Hänsel und Gretel they have to sing in two parts. And there’s a large range - they go right up to top A’s - so I have to choose the best singers.” They also learn to sing in German: a language coach is present at every rehearsal. “There are some syllables like ‘Rü’, which are really hard to say because you have to make your lips so small,” says Ben.

Between rehearsals, the children play cricket and football against the principal members of the cast. Naturally, the boys tend to win. “There’s one boy who bowled about ten people out in a row,” reports Joe. 

The rehearsal schedule does have one downfall: they have to miss school. I assume they are distraught? They all look at Mr Swinson. “Honest answers only,” he says.

“I don’t mind missing Tuesday,” says Joe. “We have double English and double maths in a row then. But I missed the best day yesterday: DT, Double Science, and everyone watched Finding Nemo.”

Nevertheless, they seem to be taking it in their stride. In fact, being part of the chorus has even made them re-evaluate their future plans. “When I’m older I want to do something I enjoy. I’m good at maths and science but I don’t enjoy them. I like this,” says Leo.

Nor has the hard work put them off opera for life. “There are people in my class who think opera is really boring, but I’ve said to them if you do opera you realise how exciting it is,” says Joe, “and how much you love the music.” 

Hannah Nepil