Lyor Cohen departs 300 Entertainment after being hired as the head of music at YouTube
By Alyssa Debonair Hip Hop Vibe Staff Writer Music industry heavyweight, Lyor Cohen worked at Def Jam and oversaw many big additions. Best-known for his work with Jay Z, Lyor also worked with DMX, Ludacris, Ja Rule, and many others. After leaving Def Jam, he worked at Atlantic Records.