Jay-z's recent signing with Universal brings forth an interesting scenario 
"Perhaps most interestingly from a FORBES perspective, the deal means that all five of hip-hops wealthiest artistsDiddy, Jay-Z, Dr. Dre, Birdman and 50 Centand ten of last years top earners are now all on labels within the Universal umbrella"
New Deal For Jay-Z, Hip-Hop Hegemony For Universal - Forbes

"Perhaps most interestingly from a FORBES perspective, the deal means that all five of hip-hops wealthiest artistsDiddy, Jay-Z, Dr. Dre, Birdman and 50 Centand ten of last years top earners are now all on labels within the Universal umbrella"
New Deal For Jay-Z, Hip-Hop Hegemony For Universal - Forbes