Who created the musical genre metal?

The creation of metal is often attributed to the band Black Sabbath. Specifically, the feel and sound of metal come from their guitarist, Tony Iommi. War Pigs is a great song of theirs which shows the feel and sound of early metal. 

Fans of metal are often referred to as metalheads. Though its appearance and lyrics can be dark, metal actually has some of the more happiest fans of any musical genres. There have been studies on this proving this to be true; often citing the catharsis that is achieved via the expression of negative emotion.