Filmmaker Anubhav Sinha and Manoj Bajpayee have joined hands for the song, Bambai main ka ba. The filmmaker says it takes strength and courage to approach certain actors with a project, and Manoj is one of them."There are some actors, you need strength to take something to them. You should feel that this work cannot be done without this person and you need this particular person. Manoj is one of those rare actors," Anubhav told IANS. Manoj is back in the spotlight rapping the number "Bambai main ka ba", which highlights the plight of migrant workers.The filmmaker has attempted to collaborate with the National Award-winning actor before, but things didn39t materialise. "I have tried once or twice before this but it did not work out because of various reasons. I gathered all my courage and went to him for this song and he said yes!" he added.