Tupac is a hip-hop icon. In the years since his death, he has sold more records than at the peak of his career. The first black artist to have become as legendary as an Elvis or a James Dean, his reputation rests on a mass of contradictions: the gangsta-rapper who eulogised the 'thug life'; the erudite young man who hoped for a political and spiritual awakening among his peers; the star who served a prison term for sexually abusing a female fan; the...