Albert Hall is standing on the gleaming main stage of the opera house. He is a 72-year-old pensioner with a part in Glyndebourne's new community opera, and is singing a jaunty eight-part harmony for the wedding scene with gusto, half dancing along, swinging slightly on his walking stick. Hall looks delighted to be exactly where he is. When we meet in the canteen later, he clutches my arm to tell me: "I'm in heaven."
This particular heaven is Imago, a new opera co-commissioned by Glyndebourne and Scottish Opera. It is written by composer Orlando Gough and librettist Stephen Plaice, and directed by Susannah Waters. Es Devlin, designer of the closing ceremony of the 2012 Olympics, and Bronia Hausman have turned the stage into a cyber world, so that this "new opera for the digital age" can explore themes of youth, age and digital technology. It won't be programmed by Scottish Opera before 2015, but the premiere will be held at Glyndebourne on Thursday, with a cast of 70 from the local community, aged between 15 and 72.
The rehearsal fizzes with excitement. "This is a life highlight", explains Michaele Wynn-Jones, a numerologist and mural painter from Eastbourne. "I never in my life thought I would get to do something like this. When I got the letter to say that I had a place in the Imago chorus, I was out in the street, punching the air."
If the project is thrilling for its participants, is it also a recruitment drive for a new opera audience? Some of the cast singing in rehearsals tell me they have never been to opera before.
While Albert is a regular attendee and avid fan, Michaele previously thought opera wasn't for her. "I thought opera was out of my league – I'm not upper class and I haven't got lots of money. But now here I am on the main stage here, opening an opera at Glyndebourne."
"This is about far more than just putting more bums on seats for other Glyndebourne activity," says Lucy Lowe, director of education.
"We are opening up opera as an art form to all these new participants. It's about offering them an excellent experience, working alongside top professionals, and exploring their own creativity with them. It's a huge journey for everyone involved, and that includes us at Glyndebourne."
For director Susannah Waters, a stronger connection to opera is, however, an inevitable outcome of the project. "It's human nature to derive more enjoyment out of the things we better understand, especially things we have first- hand experience of."
So Waters believes that the next time these participants attend an opera performance as an audience member, they will have a profoundly changed understanding of what is involved.
"One of our teenage singers tweeted yesterday that she had no idea music from an opera could be so catchy. And I am sure that this is as much due to the fun she is having, and her familiarity with the music, as it is to do with the music's accessibility."
Waters says she doesn't cut the amateurs any slack. "It's my very strong belief not to direct community performers any differently to professionals. I treat this work exactly the same as I would a purely professional piece. We ask a lot of them," says Waters, "and so they come to expect more of themselves. It has a huge impact on people's confidence and self-belief."
But while expectations are high, there is a deal of special care taken over the community cast. A member of Glyndebourne staff is appointed especially for the pastoral care of the chorus, and at rehearsal, I watch the wedding scene being restaged in order to make the singing easier. Before rehearsal, people wander around with headphones on, a fixed look of concentration on their faces. They are listening to recordings of their parts, made to help those who can't read music. As one chorus member, John Lancaster, confides to the Imago video blog: "I've got no musical training. I don't know how many beats there are in the bar – I didn't know what a bar was before this, except for the one that you lean on."
Glyndebourne is also keeping an eye out for young talent. One young vocal soloist, Zac West, was discovered through the Glyndebourne Academy. He is an A-level student with a speaking voice so resonant that it fills the auditorium. "We are helping Zac discover his voice," smiles Lowe. Down in the orchestra pit, talented young instrumental players will also perform Imago, alongside professionals from Aurora Chamber Orchestra, with conductor Nicholas Collon.
Although it's hard work, the imaginary world of Imago is clearly doing great things for its participants. Shortly before my visit, one of the older members of the chorus, Fiona, has been on local radio, describing how, while taking part in Imago, she feels "the happiest and healthiest" she ever has in her life. If opera can make you feel that good, who needs to sit around imagining a different life?
Imago is performed at Glyndebourne Thursday to Saturday, with Scottish performances in a forthcoming Scottish Opera season.