first off, if it's on mtv it's NOT hip hop (50 cent isn't fucking hip hop), secondly if it's about lots of bling with my bitches riding on my
twenty's capin some mofo it's NOT hip hop,
thirdly if the song is only two lines repeating over and over it's NOT hip hop, fourth if the verse is all jumbled together and not enunciated it's NOT hip hop, the above mentioned criteria constitute rap.
Hip hop typically has a social message that not just about how fucking awesome I am and how hot my bitches are, enunciated lyrics, a more complex beat, and requires serious talent. If you want to listen to hip hop, you have to
seek it out. It's not going to be on MTV or
clear channel
And finally if you listen to both and can't discern a single thing and think I'm full of shit go listen to
Umi Says by Mos Def (you can even find the lyrics on line), at least you'll understand the differing messages between hip hop and rap