joe handest von trapp, the youngest son of george and maria was one of three children the von trapps a total of ten. what parallels between your real life and the movie are real? >> well i think it's easier to say that the main theme of the film is accurate. and then pick out a few inaccuracies, and correct them. one is the time frame. my mother and father were married in 1927. hitler invaded austria in 1938. so there were 11 years there, which went up in smoke in the movie. >> reporter: and in real life the von trapps didn't escape the nazis by crossing the alps he said they would have been killed. rather they took a train to italy and then on to america, where they continued singing. holding the family together was maria, the nun in training turned barroness von trapp who wrote the story of the von trapp family singers. >> reporter: why do americans love this story line so much? >> it's a masterpiece of movie making. it deals with themes that are fundamental to the human condition. love of family love of a man and a woman, love of country, and i think these themes all resinate with