Andrew Lloyd Webber has reigned over musical theatre for nearly five decades and delighted millions worldwide with hit shows like Jesus Christ Superstar, Evita, Cats, The Phantom of the Opera, Aspects of Love and, most recently, School of Rock the Musical. To mark his 70th year, Lloyd Webber has written an autobiography - Unmasked, a candid and confessional account of his early life and career up to the opening of Phantom. In this imagine special, Alan Yentob talks to Andrew about the book, his bohemian childhood and the memories he's chosen to reveal.