Yes Rap has taken over contemporary musical tastes, because culture fucking sucks. I REALLY wish black people get back into playing instruments and stop this rap shit. And I love myself some real hip-hop too.
But implying that blacks can't play instruments is probably the stupidest / most ignorant / most racist thing I've ever heard. Probably the most soulful and most creative musicians of anytime were black and you can't fucking deny that. These guys have more musical talent than the entire WF membership x 100000 in their left nuts. White guys wouldn't be playing rock if it weren't for the Chuck Berry's and BB Kings of the world.
Basically every musician white guys worship was influenced by at least one of the above at one point of their lives. If not directly, then their influences were influenced by them. It goes both ways too, obviously blacks have been influenced by white musicians before them and etc.
I knew someone would take me 100% seriously.
Of course anyone is capable of playing an instrument and those guys you named put out some great music...but there is a grain of truth in what I'm saying about laziness and maybe it has a lot to do with our culture and the fact that creativity in all mediums is dying a slow death. Recently blacks have not felt the need or desire to learn how to play an instrument when they can simply "borrow" music from someone else or turn on a drum machine and incorporate that into a hip hop/rap song. It's a shorter way to success and money and women and everything else guys want. And even though we all like the shorter way to success, I don't have much respect for what they're doing. I relate it to the movies of today; all spectacle and no substance. You'd think that maybe guitars or keyboards would work their way into this type of music but I honestly don't think these "artists" are looking to expand on the music and make it better or take it in a new direction. 99% of them only want to make large amounts of money and don't care about making a lasting work of art.
You mentioned Prince. He was a good guitarist in his early days but I can't remember hearing any great guitar solos in his recent songs like the one in Little Red Corvette.
Call it our culture or whatever but I think black people have embraced the idea of making music without having to actually "make the music."