Instruction:
What hit song that was used in the Bollywood movie Don actually a reject from an earlier movie.

Response:
The song 'Khaike Pan Banarasi Wala' was actually written for the movie Banarasi Babu for Dev Anand.  However Dev Anand did not use it in his movie.  So it was picturized on Amitabh Bacchan in the movie Don.