The Sound of Music facts:
In the song 'Favourite Things' it mentions "schnitzel with noodles" this was added to rhyme with "apple strudel" because traditionally in Austria at least you don't have noodles with schnitzel.
The scene where the rowing boat overturns and Maria and the kids fall into a lake was hard on Kym Karath, who played 5-year-old Gretl. Since Karath couldn’t swim, Andrews was supposed to fall forward when the boat turned over and rescue her. Instead, Andrews fell backwards and couldn’t get to Karath in time. “I went under, I swallowed a lot of water, which I then vomited all over Heather [Menzies-Urich, who played Louisa]"
In the movie, the von Trapp family escapes the Nazis by crossing over the mountains into Switzerland. In real life, the von Trapps took the train to Italy. If they had gone over the Austrian mountains, they would have ended up in Germany—right by where Hitler had his mountain retreat.
Christopher Plummer, who played Captain von Trapp, hated the film so much that he called it The Sound of Mucus. “Because it was so awful and sentimental and gooey,” he said. “You had to work terribly hard to try and infuse some minuscule bit of humor into it.” He drank and ate away his sorrows in Salzburg, which caused him to gain so much weight his costumes had to be let out. He also admitted on the DVD commentary that he was drunk when filming the music festival.
Angela Cartright(Liesl) and Nicholas Hammond went on to bigger things. Hammond was the first actor to play Spiderman for a television series of the 70's and Angela played Penny Robinson in a sci-fi series 'Lost In Space' Julie Andrews of course went from Mary Poppins to other films. Christopher Plummer was Sir Charles Lytton, the jewel thief in the first Pink Panther film(in that film there is a mistake by Peter Sellers left in "you are Sir Charles Phantom, the famous Lytton"
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In 2007 a new version of the stage show being cast by Sir Andrew Lloyd-Webber decided to look for a new girl to play Maria and a BBC1 series was set up called 'How Do Solve A Problem Like Maria - the winner, which was decided by public vote was Connie Fisher.
Sources: Various.