Today I was listening to Devin Townsend in the car. He has an incredible range, especially for a vocalist in popular music. I also noticed not only is he an excellent singer, but he can do screams and growls without damaging his singing voice. He also can hit an excellent vibrato when he wants to, often in an operatic manner when sustaining long notes.
I got to thinking about other singers who had a wide range of vocal abilities. Although I'm not really sure Mike Patton has as good as a singing range as Townsend, as far as I know Patton has done the most versatile styles: singing, screaming, rapping, growling, scat, etc. and he's played in pretty much every musical genre one can imagine. I assume I'm correct when I say he also plays several instruments.
Then there's Gentle Giant, all of whom were virtuoso singers as well as virtuoso instrumentalists. Odds are you could the band an instrument and at least one of them could play it well.
Anyways, versatile musicians in prog: discuss!