Sir Paul McCartney 'delivered' to the ballet world

Sir Paul McCartney's first ballet score has premiered in New York.

Peter Martins, master-in-chief of the New York City Ballet, said it has been one of the greatest collaborations in his career.

Speaking ahead of the premiere, he told BBC arts editor Will Gompertz that the musician was engaged in "every aspect" of the project.

The ballet, choreographed by Martins, tells the story of an underwater romance.