Image copyright Getty Images Image caption Sir Paul's songs "exceeded expectations", the musical's producers said

Over the course of his career, Sir Paul McCartney has written films, oratorios, poetry collections, children's books and more than 100 hit singles.

Now, at the age of 77, he has a new challenge: His first stage musical.

The star is working on an adaptation of Frank Capra's classic It's A Wonderful Life, the story of a suicidal man saved by his guardian angel.

Sir Paul, who was four when the film was released in 1946, called it "a universal story we can all relate to".

The musical is set to debut in "late 2020", according to producer Bill Kenwright, whose previous credits include the West End show Blood Brothers and the touring version of Joseph and the Amazing Technicolor Dreamcoat.

Lee Hall, who wrote Billy Elliot and the recent Elton John biopic Rocketman, is penning the script and collaborating with Sir Paul on the lyrics.

"It's A Wonderful Life is my favourite film," said the Tony Award-winner. "It has absolutely everything - comedy, pathos and a rare humanity which has touched generation after generation.

"To give it a life on the stage is an immense privilege in itself, but to do with Paul McCartney is off the scale.

"Paul's wit, emotional honesty and melodic brilliance brings a whole new depth and breadth to the classic tale. I feel as if an angel must be looking after me."

Image copyright Getty Images Image caption The beloved film starred James Stewart as George Bailey. Karolyn Grimes played Zuzu, his daughter.

This is not the first time that Capra's Oscar-nominated film has been turned into a musical.

An ill-fated adaptation was staged in the US in 1986, with lyrics by Sheldon Harnick (Fiddler On The Roof) and music by Joe Raposo, a composer on the TV show Sesame Street, where he wrote C Is For Cookie and Sing - which was later covered by the Carpenters.

Initially performed at the University of Michigan, it suffered repeated delays arising from a dispute over the rights to the story upon which the film was based, Philip Van Doren Stern's novella The Greatest Gift.

By the time the first professional production was staged, in 1991, Raposo had died of cancer. A 2006 off-Broadway revival received mixed reviews, with the New York Times criticising changes to the film's plot, and the show's lack of "emotional punch."

Reviewer Anita Gates concluded: "It used to be A Wonderful Life".

A more recent adaptation, by Keith Ferguson and Bruce Greer, still tours churches and schools around the US.

'Deceptively simple'

Bill Kenwright says he harboured ambitions to turn the film into a musical long before either of the US productions took shape, writing to director Frank Capra to seek permission at the very start of his career.

Despite receiving a "lovely handwritten letter by reply," his approach was turned down. Decades later, he was offered the rights "out of the blue" and approached Sir Paul to see if he'd be interested in writing the music.

"Like many of these things this all started with an email," said the former Beatle.

"Writing a musical is not something that had ever really appealed to me but Bill and I met up with Lee Hall and had a chat and I found myself thinking this could be interesting and fun."

Kenwright said the star's initial demos "exceeded expectations".

"The songs take you somewhere you don't expect to go. They sound simple - but it's deceptive. That's Paul's genius."

Starring James Stewart and Donna Reed, It's A Wonderful Life struggled at the box office upon release in 1946.

However, it went on to become a beloved Christmas staple and has been recognized by the American Film Institute as one of the 100 best American films ever made.

Sir Paul's music has frequently been used on stage, notably in Cirque Du Soleil's ambitious Beatles show, Love.

The star also wrote a movie musical, Give My Regards to Broad Street, which was savaged by critics upon its release in 1984.

Follow us on Facebook, on Twitter @BBCNewsEnts, or on Instagram at bbcnewsents. If you have a story suggestion email entertainment.news@bbc.co.uk.