Cuba Gooding Jr. says playing OJ Simpson has scarred him; Imelda Staunton reveals she took a picnic to the Oscars; Will.i.am believes time travel will happen; and George Ezra performs live in the studio.

Cuba Gooding Jr., talking about starring in Chicago in London's West End, says, "When I was performing on Broadway in 2013 and stepped back on the stage I realised the stage is home for me as an actor. This opportunity scares the hell out of me but, it's that fear that keeps the intensity going. When they said, 'You've done Broadway, come to the West End,' there were tears! I am very excited to be here."

The actor, who is still in rehearsals, gives an unaccompanied rendition of All I Care About is Love, delighting the audience.

Asked about playing the lead in The People v OJ Simpson, Cuba says, "It really got to me. It was about exploring the culture rather than whether he was guilty or innocent and that's why I accepted the role, but it was a dark emotional journey and I am still scarred by the darkness I had to create."

Revealing that fans have corrupted his famous line from Jerry McGuire to reflect his role as OJ Simpson, Cuba says, "They now shout, 'Show me the knife!'"

Imelda Staunton, talking about going to the Oscars for her Vera Drake nomination, says, "It was a long journey so I packed sandwiches and a bag full of snacks to have in the limo. How very English of me to worry about getting hungry!"

Asked if she was disappointed not to win, she jokes, 'I'm not bitter!" Adding, "I sort of knew I wouldn't win. Because it happened to me later in life I knew I had my career and it wouldn't change my life so I could absolutely enjoy the whole thing of it without thinking, 'This is going to make me.' We partied and it was gorgeous."

Talking about her new film Finding Your Feet, she says, "It's about having a life when you are middle aged. Usually the story is with the younger people, this time it is with us and it's rich, funny and heartbreaking - things that happen at any time of life."

Will.i.am, talking about his new futuristic novel - WaR; Wizards and Robots, and asked if he thinks time travel is possible, he says, "That will happen." And on whether there might be a film of the book he says, "Yep. It will be a virtual reality experience."

Asked if he can ever blend in with the crowd with a dressed-down day, he says, "I ride my bike and have a bike outfit. I wear a mask, my glasses, a helmet and a hoodie - I look like a ninja!"

Talking about losing weight recently, he says, "I used to layer up to hide everything and wear big brimmed hats - I have big brimmed hat for when I am a little plump to make me look smaller, but now I just eat rabbit food and have lost 20lbs."

George Ezra performs Paradise live in the studio before joining Graham for a chat.