Blacks have to work twice as hard to get half the credit in the music industry...or any given industry. This is a known fact.
Just look at the 40s, 50s, and 60s. White artists were always stealing from black artists. Prime example, Elvis. Notice how a black act has to "cross over" in order to make it big in mainstream America? What audience do you think they are "crossing over" to? Certainly not the Latinos. You need to wake up and realize being white in the industry has a lot to do with success. Madonna being white already gives her an advantage because A) most of america is white, and B) Whites are the major consumers in America.
Blacks have it twice as hard whether if you want to admit it or not. And it's not playing the race card, it's called being in touch with reality. A realm of life I see you're not too familiar with.