Dr. Dre earned $620 million last year, but this year Diddy, Jay Z, and Drake all surpassed him

Forbes' Hip-Hop Cash Kings roundup is here. The annual list ranks hip-hop stars by earnings in a one-year period, and this year there are quite a few surprises. Last year, Dr. Dre made the most money in hip-hop after Apple purchased his company, Beats Electronics, for $3 billion. A year later, Dre has slid into fourth place behind Diddy, Jay Z, and Drake. According to Forbes, after coming off the big $620 million personal payday from Apple, Dre has seen his checks shrink a bit, essentially reduc...