Stephen Sackur speaks to Petula Clark, a much-loved child performer during the Second World War. Getting to the top in showbusiness is hard, but staying there is much, much harder; few stars can match the sustained success in music, film and theatre that Clark has enjoyed. She went on to have a host of hits in the UK, France, the US and pretty much everywhere else. She has worked with legendary names from Fred Astaire to Serge Gainsbourg, and continues to sing and tour. So what makes her tick? Show less