Rap mogul Jay-Z has been hard at work writing the score for Baz Luhrmann's forthcoming new feature film.

'The Great Gatsby' is due to be released at some point during 2013 and Jeymes Samuel of The Bullitts took to his official Twitter page on December 30 to reveal that he's been in the studio with the '99 Problems' hitmaker where they have been collaborating on the movie's score.

Luhrmann's version of 'The Great Gatsby' stars Leonardo DiCaprio and Carey Mulligan, and also features Isla Fisher and Joel Edgerton. It is scheduled to be released in May of this year.

Jay-Z recently made headlines after chatting with an elderly woman on a New York City subway and explaining both his life and career to her.

Watch footage of the rapper chatting to a fellow passenger below: