You’re about to perform at the Last Night of the Proms for the first time. How does it feel?
I have a mixture of feelings – I'm thrilled, exhilarated, a bit nervous. I’ve been told by people who’ve done it before to relax, to just enjoy it. I’ve got quite a lot to do this time, which is a good thing, but there’s a lot to concentrate on and I’m a wearing a different outfit for each appearance!

What’s special about the Proms?
It’s an extraordinary international music festival, probably the most important, widely-visited and watched in the world. And I’m very proud that it happens in the UK. Controller Roger Wright’s done a fantastic job covering all bases, I’d say – there’s something for everybody.

This year you’re singing two of Dido's arias from Purcell’s opera Dido and Aeneas. You've described yourself as being 'obsessed with' Dido – what connects you to the character?
I heard it first when I was 11 or 12 at school, and I thought it was absolutely extraordinary music. I just got hooked on the piece. I find the music very reassuring. It’s a real connection to the past: if that kind of thing was hugely popular then, it’s thrilling to me that it’s being performed in the Last Night of the Proms now.

How important to you is it to perform Purcell authentically?
Though I want to be authentic, the vibrato in my voice is a bit of a giveaway – it’s a 21st-century sound, but I think that’s a given, certainly in a big space like the Albert Hall. And it would be very odd for me not to use vibrato. If you want that kind of recording [without vibrato], listen to the excellent Catherine Bott version, which is the purest of the pure you can get. But it doesn’t have the kind of drama that ours has, and that’s what I was aiming for: going for 21st-century voices which have a stylistic sensitivity.

You’re also performing 'Shall We Dance' by Gershwin, another composer whose work you have something of a history with…
Yes. I used to do my own piano and voice arrangements of Gershwin pieces. I’ve always liked to do that – to make it sound like a real jazz piece. And that’s what composer Barry Forgie has done [for the Proms], I believe. I haven’t heard the arrangement yet – we’ve only just worked with piano – but he can make a symphony orchestra sound as close as possible to a proper jazz arrangement.

Trumpeter Alison Balsom and I will duet: she does the main tune and I do an answering phrase later on. I’m glad I chose that song because it gives real scope for a duet. It’ll be amazing but it’s going to be a bit bizarre. We’re going to be at the front away from the rhythm section, with microphones, so I’m a bit nervous of the acoustic control. All we have to do in rehearsal in the morning is to make sure we can hear the drums, otherwise it’s going to be all over the shop! So that slightly worries me. But I think so long as we can get the acoustics sorted out it’ll be fine.

Interview by Matt Elton

Image: Peter Warren

Related links:
Proms Diary 13: Completing Mahler
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