Musical genius

As well as the thrilling action, ‘Rocky’ is probably best known for its original soundtrack with the theme song ‘Gonna Fly Now’ being a particular stand-out.

The tune - which blares over Balboa's training montage - became a smash-hit and reached the number one spot of Billboard’s Hot 100 chart.

Composer Bill Conti recalled Stallone's initial reaction to the song and explained what drew him to the movie in the first place.

He said: "From the moment that Sly heard the whole soundtrack, he loved it and thought that that was the way to go.

"It was a very simple, almost predictable story, but what was unpredictable is that Rocky didn’t win in the end. "The film happened to have a big effect on an audience and has actually lasted in terms of being an underdog movie.

"And no one thought 40 years ago that it might do as well as it has done. It was an honest film in the sense that it was a good script with fine performances."