Check out these two videos.  One of them is Sabastian Bach (Skid Row) singing "War Pigs" with Camp Freddy.  The other one is Sully (Godsmack) singing "Enter Sandman" with Camp Freddy.

These videos were taken from a benefit concert that Camp Freddy played  for the Rivers Of Recovery in Washington D.C.  The Rivers Of Recovery non-profit is one of the premier charity groups in the nation that is dedicated to working with disabled veterans who are struggling with post traumatic stress disorder,   as well as additional combat-related psychological disorders.

In other words, a good cause as several musicians showed their support including Sabastian Bach, Sully Erna, and more besides Camp Freddy.

Sabastian belts out Sabbath's "War Pigs" while Sully, I think, does a better "Enter Sandman" than what even the mighty Hetfield does!

You be the judge.  Here are those two fan shot videos.

First,  Sabastian.

Now check out Sully's version of "Enter Sandman". I think it's better than the original!