I dunno, I kinda feel like hip hop and everything is too big and diverse to put it in one group...like even if you type in rap and then type in hip hop on a fileshare program you can notice a big difference in the artists. I also kinda think rap and hip hop songs are built differently lyric wise, rap is more freestyle ranting(cant really think of anything to explain it), and hip hop usually has a real distinct chorus and almost less of like building up in the song till one point when it climax's its(usually) a constant flow almost.....I dunno though everyone probably has a different opinion on this.