Welsh National Opera bring a new production of Richard Strauss’ Der Rosenkavalier to Birmingham Hippodrome on Saturday, and it features company favourite Rebecca Evans for the first time in the role of the Marschallin, ageing (she’s all of 36) and wondering how long she can hold on to the attentions of her 15-year-old toyboy, Octavian.

Rebecca told me how she felt after singing this huge role at the Cardiff premiere just a few weeks ago.

“I must say, a massive relief! Even though I’ve had a love-affair with the opera since 1994, the Marschallin is a different kettle of fish altogether, and it’s been like climbing Mount Everest at times, I have to say.

“But all of us in the cast certainly enjoyed the first performance at the beginning of the Cardiff run, and it was good to get one under our belts.”

And how did she feel singing the final trio, where she relinquishes her hold over Octavian and releases him into the hands of the ingenue Sophie?

“Well, it probably has to be the best music ever written in the world! It’s a ‘sopranofest’ isn’t it really? Because even though Octavian is a mezzo, it’s a very high mezzo, and it’s like having three completely differently-coloured soprano voices all singing this glorious, heaven-sent music.

“It was far more thrilling singing this trio as the Marschallin than it ever was as Sophie.”

Does Rebecca see the Marschallin as an extension of the Countess in Mozart’s Marriage of Figaro?

“Most definitely, most definitely! The Strauss is very much an hommage to the Marriage of Figaro, and the relationship between the Countess and Cherubino there and the Marschallin and Octavian here is so similar, and so delightful and charming”.

Rebecca’s early CV bears witness to many of Mozart’s “soubrette” soprano roles, but one outstanding omission is that of Blonde in the composer’s The Abduction from the Seraglio.

“I’ve never done Blonde, and I was never a soubrette in the true sense of the form. I had an extension to the top register, but E-flat was really it for me, and Blonde goes up to a top E, and I thought, you know, I wouldn’t risk it. I really shied away from it, nor was I capable or interested in singing Constanze.

“I was at the Aldeburgh School of Music for a summer course in the Mozart repertoire, and just for fun one afternoon I sang the Queen of the Night, and the teacher said, ‘oh, so we have a child Queen of the Night’. She said, ‘well done, Rebecca, but don’t ever sing it again’.

“I think of the pressure on anyone who wants to sing the Queen, or even Blonde – and the Queen is the most difficult role Mozart ever wrote – but some people are born to it. It’s like my mother would have said, it’s like shelling peas for them, you know? Whereas for me I would have had sleepless nights for six months, knowing that it was in the diary, coming towards me.

“I was always much happier with his more middle-of-the-road roles, pitch-wise, such as Pamina, Susanna, Despina, Ilia. The more lyrical roles are much better for me.”

Rebecca and I agree that the role of Ilia in Idomeneo is a wonderful one.

“It’s the role that launched me in 1991,” she says, and I interrupt her by saying it launched me in 1964, when I attended a costume rehearsal of Idomeneo at Glyndebourne, one magical summer morning in 1964 and realised that I could not operate in any other world except that of music.

Gundula Janowitz was singing Ilia there, and Rebecca joins in my enthusiasm for the singer.

“I adored her,” she says, “and I listened to her a lot singing the Marschallin, funnily enough, during my preparation. Oh, what a voice she had! That would be enough to inspire anyone, don’t you think?”

Out of all the roles that Rebecca has performed, are there any which are particularly special to her?

“Susanna in the Marriage of Figaro will probably always be my most special role. It’s probably the role I’ve sung more than any other, in more opera-houses all over the world. And the love of that role came at the age of 11, when my father bought me for my birthday the Karl Bohm recording, with Gundula Janowitz as the Countess, funnily enough.

“He bought me Don Giovanni, Magic Flute and Figaro in a boxed set, and really that’s what ignited the fire in my belly that this is what I wanted to do, even at 11. Gundula Janowitz singing that incredible Letter Duet with Edith Mathis in Figaro... it’s the best!”

We move from Mozart to Wagner. Has Rebecca ever performed anything by that composer?

“No. I’m afraid of Wagner, really. It’s just a step too far. I’m comfortable with always being very cautious, and I’m comfortable with finding my way slowly into this repertoire, of course, but time isn’t on my side, as the voice changes.

“I suppose there’d only be one Wagner role if ever, for me, and that would be Eva in Mastersingers.”

Are there any roles on Rebecca’s bucket-list?

“Alice Ford in Falstaff, which I’m going to do in Liverpool with Bryn Terfel in the autumn in two concert-performances. So that’s a fantastic introduction to a role I’ve longed to sing forever, and maybe, maybe, Eva in Mastersingers.”

Finally, there is a famous Welsh Labour politician sharing the same name with Rebecca. Do they ever get confused?

“It’s hysterical, but we’re very good friends, and we know each other well. We were at a function recently where we met for the first time, and she’s an absolute delight. She gets a lot of emails for me, and I get a lot of emails for her!”

  • Rebecca Evans sings in Welsh National Opera’s production of Richard Strauss’ Der Rosenkavalier at Birmingham Hippodrome on Saturday (6pm).