Serj Tankian of System of a Down he has such a wide range of vocal abilities, from being able to scream with the best of them, to carrying a soft melodic voice (even in the same song)....also, he's an activist against the Iraq war, as well as human rights, among other things, and it reflects in his lyrics....also, he uses a lot of metaphors a lot of people don't like "System" because of the screaming that they sometimes do, but, if you can just "listen" to them, listen through one of their albums and hear the words and their message....you'd be surprised to find out that they're not just screaming a bunch on nonsense to make "noise"....there really is a message