As a world-famous conductor, you have received so many honours, so how important is preparation to you?

I think I have to look alright on the rostrum. First of all, people are paying a lot of money to hear us perform, but they are also looking at us for two, maybe three hours and so they want to see us looking the part, that's very important.

What do you usually wear?

Usually tails, and white tie. This is a way for me to get the concentration going, and that's what I pray for every time – that the concentration is there before I start conducting.

What has influenced your style?

I remember going to see preachers in Wales from when I was very little. Looking back, they were performing too, the way they held an audience. I was aware every time I looked at them in the pulpit, or now in the church, that they dressed properly. In a way, they were saying 'Here I am, you're looking at me, that's what's important to me'. Sometimes I stand on the rostrum and I can see some of the orchestra have dirty shoes and I think 'Oh Lord, no!'. They can hide, but I can't!

What about when you're rehearsing?

I'll wear a shirt, maybe a jacket, but I'll take the jacket off. Never in jeans – always a nice pair of trousers. Always smart. Sometimes an orchestra walks in to the rehearsal in jeans and the like, and you'd never believe they were the same people performing in the orchestra that evening. But I'd never go in front of them looking like that. You're in charge, and that's important.

Being smart is important to you, and I notice that a lot of these colours are very similar – light blue, pink, pastel colours. Why's that?

Yes, I think they suit me, I don't know why. Sometimes I wear dark things – black usually.

What's the background behind this outfit?

This is what I wear for the really big concerts – say the Albert Hall. They have been made especially for me. They fit properly and they're light. The fabric is very good, so they don't look terrible after I've been conducting for a long time. The linings are different colours so that I can tell the difference between them – but everyone's picked up on that and think it's my trademark. When you're going to conduct in the Royal Albert Hall or St Davids Hall, you want to look okay.

And what about shirts?

I wear a white shirt with a Marcella Front. And then a waistcoat to match, and a bow tie.

There's two stand out waistcoats here – you wouldn't go missing in these...

Well, these are a bit of fun really. We do the Welsh Proms and during the second half of the last night, we have some fun with the audience. There was a woman in Cardiff who owned a shop and she made these for me to wear on the last night of the Proms. Then the National Youth Orchestra of Wales made a waistcoat for me to wear on the last night. This one is Hughes tartan and was made especially for me. It's lovely, isn't it?

You've had some amazing experiences and have travelled the world with your career. Do you buy things abroad?

Since I go to Capetown during their summer, it's very hot. The city hall is lovely, but there's no air-conditioning. So they said to me, 'Don't wear tails, wear whatever you like'. So I found this black shirt. The orchestra took their jackets off, and they were in white shirts and bow ties with me all in black.

There's one white jacket here. When do you wear this?

I'd wear this in the summer in the UK. Of course, during the summer we play a lot of outdoor concerts, so this looks great. Quite often there are lots of different coloured lights on us when we are performing outdoors so it looks nice against the white.

And I've noticed this pocket watch of yours, what's the story behind that?

I found a normal wristwatch uncomfortable when conducting, so I got this one. It's out of the way and so I have more freedom when I'm conducting.