Rap icon JAY-Z is surprised he has been so successful in the music industry - because he can't sing a note in tune. The hip-hop mogul - real name Shawn Carter - is convinced he only became an internationally renowned star because his lyrics make up for his poor vocals. He tells MTV.com, "My voice is less than 10. Let's just say that. "I never thought I had a great pitch... What I do is overcompensate with words and flow."