Shah Rukh Khan has just sung a song 'Khaike paan banaras wala' in Farhan Akhtar's 'Don'. The film is a remake of the original Amitabh Bachchan starrer Don. Shankar Mahadevan of trio music director Shankar-Eshaan-Loy says, "SRK grasped the song beautifully and we worked very hard on it." Farhan is impressed by SRK's performance. Shaad Ali managed to rope SRK and Amitabh Bachchan to shake a leg for Yashraj's 'Jhoom Barabar Jhoom'. Shaad, Gulzar and Shankar-Eshaan-Loy have worked very hard to give the title number a special flavor. Big B is looking forward to work with Shaad again after BAB. Far away from London, Bachchan says, "I play the sutradhar who links the storyline, and carries the plot forward. Its just a song that will require four days of work from me."