You’ve been doing Heliane for nigh-on five years now. What effect has the role had on you as a person?
Heliane bumps up my confidence levels. It’s one of the hardest roles I’ve ever sung. I go from the very lowest notes I can manage to the very highest. It’s got me singing tonal shades that I’d not known before.

What is it about the role that’s so hard?
The two arias are set in keys that are hugely difficult for a soprano. Vocally, it’s risky territory; it’s like I’m clambering across a mountain range, teetering on cliff-edges; I get to one summit, only for another peak to appear. I don’t get back down to base camp until the curtain falls.

HELIANE was your first collaboration with director Christof Loy, and you’ve been working with him off and on ever since. What’s special about the way he works?
He’s endlessly creative. He sets up these lovely scenarios and he has a fantastic feeling for architecture that invites people to look at things from a fresh perspective. And he has affected me on a personal level, too. He kindled a light inside me that allows me to sound out a character down to her very depths. He gives me the tools to extract from each note colours that I’ve never even heard before. His directions often stick in my mind for months afterwards. His words work away within me.

Christof Loy has described the Heliane role as being a “sublimation of Eros over the singing”. What does that mean?
My way of singing Heliane involves exuding a sensual desire, coiling, playing, tingling, entwining.

What has Heliane taught you?
Heliane lets me believe – in the power of love, in the power of connection, in the opportunities that spring from that.

What’s your favourite bit in HELIANE?
I love the second aria, when Heliane’s calling on God, imploring him, to resurrect the man she’s suddenly fallen in love with. Everyone’s wondering how that’s going to happen, but the impossible comes to pass and the stranger wakes up. The aria always reminds me of the stresses that were placed on the love between Korngold and his wife. Both sets of parents were against the union and they had to go a year without seeing each other – but the couple won out in the end and their love triumphed. The aria contains all that: the impossibility of love; death and resurrection; utter faith.

Korngold wrote an immense score and the orchestra works up into a welter of sound. How do you manage to hold your own against this ecstasy of orchestral power?
The boring answer is: it’s my job. To bring off this role, I have to be totally centred and focused. I have to keep rigidly to the technical and vocal details that I’ve been practising. I can’t be matching my singing to the orchestra: if I did that, my voice would be drowned out. So I’ve come up with a map of notes, vowels and words that I keep to, to make myself heard. And if I’m honest, this map also helps to ensure that I’ll still be singing in 25 years’ time! Because if I get swept up in ecstasy, it ruins my voice. It can work for one performance – and then it’s magic – but I wouldn’t be around for the long haul if I let intoxication take over.

In one scene Heliane drops all her clothes on stage. What does that scene mean for you?
That scene is pretty harmless compared to the musical risks that I run singing the role. Being naked is not a massive thing for me. I don’t spend a lot of time thinking about it. Perhaps I’ll have a different take on it in the future. But basically, this nude scene just adds to my collective body of work.