Legendary film composer Hans Zimmer will be forever grateful to Barry Levinson for asking him to score the 1988 film 'Rain Man'.

The 61-year-old German musician admits the call asking him to score the acclaimed 1988 comedy-drama movie starring Tom Cruise and Dustin Hoffman - who won the Best Actor Oscar for his portrayal of Raymond Babbitt who is an autistic savant - was the moment his career changed forever.

Zimmer won the Best Original Screenplay Academy Award for his music for 'Rain Man' - which also won the prestigious Best Picture Oscar in 1989 - and he was then asked to compose the score for Bruce Beresford's 'Driving Miss Daisy', which also went on to be a Best Picture Academy Award winner, and from then his reputation was established.

When asked if the 'Rain Man' job was a life-changing moment, he said: ''Totally. Completely. [It was] THE CALL - this is all in capital letters.''

Zimmer has worked with numerous directors over the course of his career, most recently penning the music for Steve McQueen's new heist thriller 'Widows'.

He has collaborated with Christopher Nolan on several occasions and he enjoys working with the director the most because he gives him ''intellectual challenges''.

Zimmer said: ''He knows I get bored easily. So he sets up certain intellectual challenges for me, things which are nearly impossible to solve, and all the music gets written before he makes the movie. Because he knows I have a good memory and I can keep a shot list in my head like nobody's business. So we can play this game.''

The composer worked with Nolan on his 2014 sci-fi movie 'Interstellar', which starred Sir Michael Caine as a NASA physicist who wants to save mankind from a dying Earth, and admits he felt ''vulnerable'' when he first played the soundtrack to the filmmaker.

Zimmer added: ''Chris comes by. I can't look at anybody when I play them something for the first time because it's the only time I get really vulnerable. I just play him the thing and I turn around and go 'Well, what do you think?' He pauses for a moment and goes, 'I suppose I'd better make the movie.' ''