Now she has returned to the stage in spectacular style, in Ragtime at the Piccadilly. As she told lastminute.com/theatrenow, she's delighted to be back onstage: "There's something very special about the West End, but when you're coming into it in a major musical there's an even greater kick to it!"

Can you tell us a bit about the show? "It's a musical about the experience of being American in the early twentieth century. It's a story that focuses on three families, and through their lives you experience the changes and challenges that faced everyone at that time. I play a mother who's the focal point of her family, the glue that holds the whole thing together."

Has it been a long time in preparation? "Yes! I was first approached to do it four years ago, then the show sort of disappeared — after an earlier appearance in Canada — but the end result that we have now, and which opens at the Piccadilly tonight, works brilliantly and is clearly going to last, judging by the audience reaction."

People like musicals in times of international tension. "Well, they certainly like this one! I think that's because, as you'd expect with a book by Terrence McNally, it is a very strong story. You see three families ripped apart by events: it isn't a pretty-pretty sort of show.

"On the other hand, the tunes are fabulous, and the sets and costumes are wonderful. And audiences react to it. We did a concert version in Wales to a full house, and although there wasn't a stick of set or props, people were on their feet at the end, going bananas. That's an indication of the strength of the story, its emotional hold. When you add to that a full set and costumes, you have something that's breathtaking." You're working with your sister, Sonia, on this show? "Yes, she's producing it, but the reason we're both associated with the project is our separate and joint faith in it. She said to me that she couldn't imagine a more powerfully, uncluttered example of storytelling on stage, and I agree."

Where does Ragtime as music come into this? "Ragtime was new music in the period in which the story is set — before the First World War. It's hard for us to associate music like that with something new and radical, as it by definition appears very 'period' to us, but this is a musical that is partly propelled by the sheer exuberance of the music. After you've seen the show, you'll understand why Ragtime was such a popular musical form when it first arrived on the scene!

"On the other hand, Ragtime as a musical has a variety of musical styles to reflect the different musical traditions of the families on whom the story is centered — Jewish, Black, white and wealthy Middle America. So the show has a very rich score."

The early years of the century weren't great ones for women, by and large. Is that reflected in the show? "Very much so. There's a strong vein of feminism in Ragtime, and one of the characters featured is Emma Goldman, who was an amazing campaigner for the women's rights movement. We think of the Edwardian era as some sort of golden age, but actually it was a time of a tremendous explosion of ideas, of energy finding new outlets, of people being politicized — and of this new music that swept the Western World."