'Sound of Music' Secrets Exposed: Brutal Injuries on Set, Filming Scenes While Drunk and The Hollywood Icon Who Almost Landed The Lead Role Over Julie Andrews

Breathtaking camera work, catchy songs by Broadway legends Richard Rodgers and Oscar Hammerstein and Julie Andrews' sweet performance as beloved nanny Maria von Trapp made The Sound of Music a classic film, RadarOnline.com can reveal.

It's remained a fan favorite since 1965. Here are some of the stunning secrets behind the making of this iconic musical.

The Sound of Music focuses on the heartwarming story of a free-spirited nanny brightening the lives of seven children and their widower father.

But the movie, and the stage musical that preceded it, also recounts the serious drama of the von Trapp family's escape from Austria as the country was taken over by Nazi Germany.

The real Maria von Trapp told her family's tale in the book The Story of the Trapp Family Singers, and Hollywood was eager to snatch up the rights – but only wanted the title.

However, Maria stood her ground, wanting her family's entire adventure to be told.

In 1956, Paramount Pictures purchased the United States film rights to the book, with the intention of casting Audrey Hepburn as Maria. But the studio eventually dropped its option, clearing the way for the stage version of The Sound of Music, starring Mary Martin.

The musical won six Tony Awards in 1960, including Best Musical, and later that year 20th Century Fox bought the film adaptation rights to the stage show for $1.25 million.

Rodgers added two new songs to the movie, I Have Confidence and Something Good, for which he wrote the lyrics as well as the music because Hammerstein died in 1960 and never saw the film's blockbuster success.

Andrews was the one and only choice for Maria for screenplay author Ernest Lehman. Director Robert Wise had Andrews at the top of his list but was also considering Grace Kelly and Shirley Jones.

But when Wise saw Andrews in a pre-release screening of Disney's Mary Poppins, he told Lehman: "Let's go sign this girl before somebody else sees this film and grabs her."

Casting for the von Trapp children began in 1963, and some of the kid performers who were interviewed or tested but not hired included Mia Farrow, Patty Duke, Lesley Ann Warren, Geraldine Chaplin, Shelley Fabares, Teri Garr, Kurt Russell and The Osmonds. New choreography had to be created for the film because that which was used for the stage was too restrictive.

The husband-and-wife team of Marc Breaux and Dee Dee Wood, who had worked with Andrews on Mary Poppins, reworked the singing and dance sequences.

But no one was allowed to change the musical arrangements, due to Rodgers and Hammerstein's contract. Scenes from Maria's bedroom, the abbey cloister and the graveyard were all filmed at 20th Century Fox studios in Los Angeles before production moved to Salzburg, Austria.

The movie's opening scene of Julie Andrews joyfully twirling on a mountaintop looks effortless, but major work went into filming that magical moment.

Not only was it rainy throughout production, the helicopter carrying a daredevil cameraman strapped to the side kept knocking Andrews over.

"This was a jet helicopter," she recalled. "The downdraft from the engines just flung me into the grass, and so we did this about six or seven times and I was spitting dirt."

Christopher Plummer, who starred opposite Andrews as Captain von Trapp, hated the movie so much he's referred to it as The Sound of Mucus.

"It was so awful and sentimental and gooey," said Plummer. "You had to work terribly hard to try and infuse some minuscule bit of humor into it."