There’s a South American flavour to Music Theatre Wales’s newest opera, which can be seen at the Oxford Playhouse on Sunday following its world premiere at the Royal Opera House’s Linbury Studio earlier this month.

Letters of a Love Betrayed is based on one of the 23 tales in the Scheherazade-type collection, The Stories of Eva Luna, by Chilean writer Isabel Allende. Set in Colombia, it is a poignant but ultimately heart-warming tale of deceit and betrayal, and the indomitability of the human spirit.

The story revolves around the orphan Analia Torres, whose lonely childhood at a convent school is enriched by a regular flow of tender and beautiful love letters. Later, trapped in a loveless marriage, she feels betrayed by the letters — until she discovers their secret.

“The story is so well chosen,” director Michael McCarthy told me. “It is an operatic story — the characters live in their emotions, particularly the central character, Analia. It’s a really vibrant opera, with the characters going through darkness and stress in order to cast greater light on the relief at the end.”

The story has been given the operatic treatment by librettist Donald Sturrock, who has retained the elegant lyricism of Allende’s original text, and Jamaican composer Eleanor Alberga, whose vivid score draws upon the traditional sounds of her own country. Together they have created the kind of intimate and potent chamber opera for which Music Theatre Wales has become renowned. “I think what Eleanor’s done with it is really exciting because the characters feel very real,” said Michael. “It’s an incredibly colourful score, not exotic, but evocative of the world in which the opera is happening, and indeed what the characters are going through themselves.”

We were talking just as the production was going into rehearsal, and Michael was clearly enjoying the challenge. “It’s going really well. It comes off the page very well indeed.

“Like all brand new operas, we haven’t had the chance to hear the opera in advance, and that’s always a big challenge. You have to work from the music outwards. I’m always very clear at the start of an opera rehearsal that the text for an opera is not simply the words that you have, but more importantly the way that the words are used and set in the music. The score is the text, and whilst I can read it in the quietness of my room, it’s not the same as being in the room and hearing it in front of you. But that’s the excitement of it too. “I think it will come across very clearly and very strongly, and it will be an intense drama, but one of intense joy at the end. And it will be quite magical.”

Interestingly, the opera was originally developed through a series of workshops with Opera Genesis, the ROH’s opera development programme, followed by a week-long workshop run by Michael and his MTW co-founder, Michael Rafferty. The result was a co-commission by the two groups, who are also co-producing it.

“The workshop was really interesting and exciting,” said Michael. “The piece clearly had an operatic heart, and Eleanor was really able to bring it to life with her music. We were able to explore the piece further, to talk to Eleanor and Donald about how the piece might develop, and have a look at it ourselves and see whether it would be a work that we would like to take on and commission. And that’s what happened.”

The opera is scored for six singers and an ensemble of fourteen, which includes a tiplé — a Colombian guitar. Oxfordshire soprano Mary Plazas is creating the central role of Analia, which presents its own particular challenge in that she has to convincingly portray the character from a nine-year-old child to a 25-year-old wife and mother. Joining Mary in the cast are tenor Christopher Steele as Luis, Analia’s detested husband; bass baritone Jonathan May as Eugenio, Luis’s uncle; and mezzo Arlene Rolph as the Mother Superior.

With a powerful storyline and a top notch cast, it seems that Letters of a Love Betrayed has the perfect mix. Michael is optimistic that this will be yet another landmark production for Music Theatre Wales, following in the footsteps of previous productions such as House of the Gods, Julie and For You.

“We’re hopeful that this opera, like some of the others we’ve commissioned, will slowly but surely enter the repertoire. That’s partly what we’re interested in as a company; discovering new works, and bringing new works to the stage that then have a life of their own.

“It’s extraordinary that nobody seems to have set an Allende text for an opera in the past. This is an opera that will appeal to opera audiences, and those who like to come to the theatre for something new. For the adventurous and those interested in something new, this works a treat.”

lLetters of a Love Betrayed is at the Oxford Playhouse on Sunday, October 11, at 7.30pm. There is also a pre-performance talk by Michael McCarthy at 6.30pm. For tickets, call 01865 305305 or visit oxfordplayhouse.com