4. Dwayne “Lil Wayne” Carter, $15 million (tie)
The lyricist reportedly wrote his first song at age 8 and signed a record deal with Cash Money a year later. Today he’s one of rap’s richest, despite serving eight months in jail last year. His latest release, I Am Not A Human Being, made him the first artist since Tupac Shakur to have a No. 1 album while incarcerated.