When Mirror reported (on October 24) that Anurag Kashyap is prepping up to direct a Hollywood film next year, the director had mentioned about a song in his upcoming film, Bombay Velvet, that remains to be shot. It's four days' work and will be shot early next year, he had then told us.

Now, Mirror has learnt that it will be a jazz number set in the swinging '60s. Interestingly, the song will not be directed by Kashyap but his close associate and the director of Udaan and Lootera, Vikramaditya Motwane. Revealed a source close to the film's unit, "It will feature not only Ranbir Kapoor and Anushka Sharma but also Karan Johar, who plays a media mogul in the film. The makers are currently conceptualising the song. It will be shot on a sweeping scale and will convey the general idea of the film. But it won't be a part of the film's narrative. It's a music video which will be used for promotions."

The source added that Motwane will direct it because he is great with music videos which seamlessly sync with the film's theme. "In Katiyabaaz, an earlier collaboration, Motwane was brought in to direct just the music video and he did a great job," said the source.

The song will be composed by Amit Trivedi and will be shot in Mumbai.