Nasir bin Olu Dara Jones, better known by his stage name Nas, is an American rapper and entrepreneur. Rooted in East Coast hip-hop, he is regarded as one of the greatest rappers of all time. From Wikipedia
He said nerves about working alongside Pusha T, No Malice and Pharrell Williams drove him to re-record his guest verse on ‘P.O.V.’ up to 100 times.