Singing has changed lives, freed slaves and stopped world war. Mark Twain sang and saved his career. Harriet Tubman sang and freed slaves. Dr. Martin Luther King, Jr. sang and changed civil rights in America. Thousands of unsung people have overcome fears, remedied ailments, and found hope by breaking into song.Sing and Change Your World! combines "chicken soup" inspiration with "Mozart-effect" musical power to demonstrate the impact of singing on ordinary life. Thematic chapters present historic characters, modern celebrities and everyday people who changed themselves and their world with a well-timed tune.