Sweeney Todd is one of Stephen Sondheim’s best musicals. The Broadway show of the mad barber that slays his customers and his equally mad partner who turns them into meat pies starred the lovely and talented Angela Lansbury. If you only know Angela Lansbury as that sweet old lady on Murder She Wrote, it is a real wonder to hear her sing about The Worst Pies In London. Sweeney Todd is an amazing musical filled with great songs and one of most intriguing stories to find its way into the usually sickly sweet waters of Broadway.As a general rule they…