After being an underground rapper, Woo signed with YG Entertainment. He released his first album, Masta Peace in 2003, and his second album Brand Wu Year in 2007.
In 2014 he was one of the producers of the talent show Show Me The Money 3.
He wrote several songs for his label-mates, for example project duo Hi Suhyun, solo singer Lee Hi and girl band 2NE1. As of April 2015 he has 74 songs credited to his name at the Korea Music Copyright Association.