When Sweeney Todd first opened in London 25 years ago it was not well-received. Sondheim has always been hurt by this reception. “It was my love letter to London.” But now, he thinks he understands. “A friend of mine, the playwright John Guare, said that it was as if the British had come to the States and done a serious musical of I Love Lucy. “And we would think, Don’t they know that’s a silly comedy? Well, I think maybe, with Sweeney Todd, people thought that the Americans were taking a melodrama just too seriously. How pretentious! “