Death Metal Vocal Exercises [VIDEO]

We all know that a singer can't go out on stage or into the studio without warming up their vocals.  Death metal is included in that, and I bet you have never seen vocal exercises like these. 

To me, it sounds a lot like cookie monster on Sesame Street.  So who is this vocalist?  His name is Olle Ekman from the band Deals Death.  They hail from Sweden, surprised?   I have really been into the death metal scene.  I never got the appeal, but I do like that someone posted this video because it is hilarious.