Propaganda
Superstar
depends on the genre tbh, i guess for more rap stuff a beat maker might master a beat for themselfs not thinking a rapper will lay something down, it happens
nah, it doesn't depend on the genre, man.
you gotta think of the vocals as one of the instruments...in fact, the MAIN instrument, especially if we're talking about rap/hip-hop. you wouldn't mix and master a song then add a bassline afterwards. so if you have a choice, you certainly shouldn't do it with the vocals.
make a solid mix of your beat for dudes to rap over, when you have the vocals, do your full-on mixdown. then you master. once. mastering it twice doesn't even make sense.