Gary Oldman talks about brushing up his English to play a Brit, Toni Collette reveals meeting Madonna was embarrassing and Nick Frost says he hates being asked to dance. British indie band London Grammar perform live in the studio.

Gary Oldman, talking about moving from starring in films with a cult following to working on Harry Potter, says, "My fan base went from 40 to four (years of age) after that. The fans are so genuine and very sweet."

And on his latest blockbuster, RoboCop, he says, "The first one was in 1987 and then it was very much science fiction and now it's science fact. It made sense to me to re-boot the film, we've caught up with ourselves." Asked if there will be more RoboCop films, he says, "It depends. It's got to do its thing at the box office, but they're hoping it's a franchise. I've been really lucky with franchises."

Asked if there is another Tinker Tailor Soldier Spy movie on the cards, he says, "I have no idea, but it would be nice to play Smiley again."

Revealing he had to have a dialect coach to help him portray Smiley, he says, "I have lived in America for so long, my kids are American and that's what I hear around me every day and occasionally weird sounds that I don't notice slip in. I had to brush up my English!"

Talking about starring in Dracula, Gary reveals his preparation for the role was somewhat unorthodox, "Francis Ford Coppola sent me a coffin to try out. One night I went out for dinner and everyone ended up at my place and at some point I wanted them to leave so I opened the garage door and the light came on and instead of a Porche under the light, it was a coffin. I never saw those girls again!"

Toni Collette, famously good at accents, reveals she almost gave up on a part as the accent was too much of a challenge, "Glassland was filmed in a part of Dublin with a very specific accent. I loved the script but I was very nervous about doing the accent. I arrived on the set and sat down with a dialect coach and turned myself into a knot. I actually called my husband and cried and said, 'I cannot do this, I think they are going to have to re-cast.' It freaked me out so much but I relaxed and just did it. I was at least consistent!"

Talking about her TV show Hostages, which she describes as a "15-part movie," and asked if there will be another series, she says, "I don't know, but I can't imagine there will be. I don't know where it would go," teasingly adding, "Something really big happens at the end."

Revealing an embarrassing encounter with Madonna, she says, "It was a long time ago at a party in LA and it was all really new to me and Harvey Weinstein said, 'You must meet Madonna,' and I was like, 'Why would she want to meet me?' I got dragged over and it was so embarrassing. I was uncomfortable and overwhelmed and she said, 'I've heard your movie is really great.' And I said, 'Well, I know you're really great and you must be really busy so fly, fly like the wind.' And that's what I said to Madonna. And she did, she left!"

Nick Frost, talking about learning to dance for his film Cuban Fury, says: "I trained for seven hours a day, seven days a week because I wanted to be able to dance. I like to dance but I don't like people to watch me. I ruined my wedding by not really wanting to dance with my wife because everyone gathered round. Asked if he has kept up the dancing, he says, "No," jokingly adding, "It is actually annoying to be asked to dance because it was for a part. If I had played a murderer, no one would ask me to kill someone!"

He also reveals that some of his preparation for roles has landed him in trouble, "In Spaced I was a weapons expert and had to strip a MP5 Machine gun blindfolded so they gave me one to take home - it didn't fire or anything. I'd done it a few times when I pulled off the blindfold and there were six armed policemen streaming in and screaming at me. A woman had seen the barrel of the gun sticking out of my bag and called the police. My voice went very high and I said, 'I'm an actor!' I was told later that they had blocked the road off and had a sniper and if I had pointed the gun at them, they would have shot me!"

London Grammar performs Strong before joining Graham for a chat.