Can you tell us something about Hollywood Party at the Queen Elizabeth Hall? "It's an evening of songs from the movie musicals, hence the title, and it'll be presented by Malcolm Laycock, who also presents BBC2's Big Band program, with me as the singer and the Piccadilly Dance Orchestra as the band. Ruth Leon is directing it."

Is this a change of direction for you? You're mainly thought of as a musicals star yourself, given your roles in Cats, Annie Get Your Gun, Dames at Sea, Side By Side By Sondheim... "I've been in a lot of musicals, certainly, but I've actually done a lot of concerts in recent years. It's something I enjoy very much, and in the ten years or so that I've lived in London, I've done a fair amount of them."

Are you going to wear a "period" outfit? "The songs and the styles that we cover range over several decades, focussed on the 20's, 30's and 40's, so I'll have something that looks fairly period in the sense of pre-war, without being too specific. It certainly won't be the sort of slinky number you'd wear for a cabaret evening, though."

Speaking of cabaret, how do you find London as a cabaret city? "It isn't really! There's only Pizza on the Park. But that isn't a criticism of London, as such. I think there's really only one cabaret city, and that's New York.

"With cabaret, you need tables, you need champagne, you need to be able to eat as well. That sort of venue is hard to find, whereas with a concert, like Hollywood Party, you need a theatre or a concert hall, a band, and you're away!" Do you have to use different vocal techniques to sing songs from different decades? "The change in music from, say, 20's to 30's to 40's and on is really one of orchestration. Different times had different styles, which is why period songs are often done differently from the way they were originally intended to be performed.

"So it's not really a question of changing my voice. After all, Fred Astaire had the same singing voice through his career — it was the orchestration that changed. If I want to get a song right, then I listen to records from the time when they were first written and performed, and that gives me the key to how they should be sung."

Hollywood Party is a one-off event. Have you any longer-term projects lined up? A musical, for example? "Yes, there's something in the pipeline, in which — speaking of Fred Astaire — I'd appear alongside a very well-known dancer. And a sexier one than Fred! But I can't really say any more about that at the moment; other than that, he would be dancing and I would be singing — that's how our respective characters would communicate."

Can you give us a clue as to the songs you'll sing in Hollywood Party? "That should be a surprise, too! But "Lullaby of Broadway," "They Can't Take That Away From Me" and "Let's Face the Music and Dance" will be there among the other classics. Book a ticket and see!"