Musician Sir Paul McCartney is to write his first original orchestral score for a ballet performance.
The former Beatle is collaborating with the New York City Ballet company (NYCB) on Ocean's Kingdom.
"I am always interested in new directions that I haven't worked in before, so I became very excited about the idea," Sir Paul said.
The production's world premiere will take place on 22 September. More performances will be announced later.
In an interview with The New York Times, the 68-year-old said the show was a love story based in two fantastic worlds - the "pure" ocean kingdom, and the earth kingdom with its "sort of baddies".
He explained that when earth meets water, love happens, and "you'll have to see whether the couple make it".
He added: "The sheer athleticism is the most astounding thing. It's like a meeting of the Olympic games and art, and I find that fascinating and challenging for me, to see what can be done."
Sir Paul was asked to consider the collaboration after meeting NYCB's ballet master-in-chief Peter Martins at the School of American Ballet's Winter Gala last year.
"Like the rest of my generation, I grew up being a huge fan of The Beatles so I was thrilled to meet him," said Martins.
"After I got to know him a bit, and knowing of his great love of composing classical music, I asked if he might be interested in doing something for New York City Ballet, and I am ecstatic that he has agreed to write a score for us."
The 50-minute production will consist of more than 40 dancers.
In 1991, Sir Paul wrote the Liverpool Oratorio with Carl Davis for the Royal Liverpool Philharmonic Orchestra's 150th anniversary.
Since then he has released Standing Stone, Working Classical and 2006's Ecce Cor Meum (Behold My Heart).