I've said it before and I'll say it again...not everyone can scream (grunting is debatable) like that day in and day out without the proper know how and training. You will rip your vocal cords to shreds within a couple of weeks, months at the most. You are going to do it a lot quicker then a singer would too. Now I'm in no way trying to say it's even in the same level of talent as being a good/great singer because that would be stupid. Most great singers have the natural ability and it's just molded and trained. Very few start out totally sucking and become great. But there have been bands that have broken up because the lead couldn't cut it anymore or their vocal chords were too weak to be able to scream all the time. There are also a lot of people who's screams sound better (to me atleast) then others and people do have uniqueness in their styles/voice/etc. But the whole "any old muthafucka off the street can..." has been said thousands of times of rapping too by people who don't like and/or get it. So to me that argument holds no merit.
