As Johnny Rotten, he was the lead singer of the Sex Pistols - the world's most notorious band, who shot to fame in the mid-1970s with singles such as 'Anarchy in the UK' and 'God Save the Queen'. Via his music and invective he spearheaded a generation of young people across the world who were clamouring for change - and found it in the style and attitude of this most unlikely figurehead.