All It Took for Me was 10 Seconds into "Ace of Spades"

A Headbanger's Headache.  (The New York Times, 7/11/2014)

I've never been a fan of heavy metal.    Doctors drained the fluid from his brain (it took six days of hospitalization after the surgery), and the man recovered completely. The case report appeared in The Lancet. 

But, hey, maybe I need to add a qualification here, based on Wikipedia's description of the English band UFO.

...a transitional group between early hard rock and heavy metal and the New Wave of British Heavy Metal.

Phenomenon (review offered with serious reservations), released in 1974, remains one of my favorite albums.  I'd call this release more hard rock than heavy metal.

The appropriate cut to share.