What was the first heavy metal album to hit no. 1?

The answer is: Metal Health. Quiet Riot may not be the first band you think of when revisiting the pantheon of metal's all-time greats, but they hold a unique position: the first band to have an album classified as heavy metal top the Billboard 200.Not to mention, Metal Health is one hell of a pun."Metal Health (Bang Your Head)" and "Cum on Feel the Noize" (terrible spelling, guys!) are still great tracks to get pumped up for whatever the day holds.Source