It is one of the most successful musicals of all time, and is still captivating audiences 50 years later.

'The Sound of Music' burst on to cinema screens back on March 2nd in 1965.

It was based on the true story of the von Trapp family in pre-war Austria, and includes some of the best-known songs - like 'Edelweiss' and 'Favourite Things'.

It all began with Maria von Trapp's 1949 autobiography 'The Story of Trapp Family Singers', on which the film was based.

Maria von Trapp's photograph from her Declaration of Intention at US immigration on January 21st, 1944 | Image: The National Archives 

It has gone from a motion picture to a stage play, having played to audiece's in London, Edinburgh and Manchester. It will also play Dublin's Bord Gáis Energy Theatre in August.

However, some inaccuracies persist over how authentic the film version was to von Trapp's book.

Johannes von Trapp, the youngest son of Maria and Georg von Trapp, told the BBC his eldest sister was not who she was made out to be.

"In the real family my oldest sister was Agatha and she was a very introverted person," he said.

"The thought of her doing that song and dance routine with the telegraph boy had us all rolling in the aisles in stitches," he added.

In the film, the couple marry in 1938 and as Johannes says: "It was quite tough enough with seven kids for the movie company."

Photographs from the von Trapp's Declaration of Intention documentsat US immigration | Image: The National Archives  

The von Trapp children also already played music before Maria came to their home - but he added that: "My mother was the energy and the instigator that took them to almost concert quality."

Another change, Johannes says, was the portrayal of his father, Georg.

His son said he was "a very charming man, generous, open, and not the martinet he was made out to be both in the stage play and in the film."

The family lost all their money when the Austrian bank that held it failed in the 1930s.

They left Austria when the Nazis invaded in 1938, travelling by train - not on foot, as depicted in the film - to Switzerland and then on to New York by boat.

From there they continued to give performances and later bought a farm in Vermont - where the family still runs a hotel, the 'Trapp Family Lodge'.

Whatever the case, the story and its outcome still resonates with people today.

As was evident at the Academy Awards last week, where singer Lady Gaga paid tribute to some its most famous songs: