response: Oh, interesting to know.  You may know Judas Priest?  He actually helped the genre evolve.  He got rid of the influence of blues.  And Motorhead gave the music an growing emphasis on speed.
original_response: I like Led Zeppelin the most out of those three. I also enjoy Judas Priest.
history: Do you like heavy metal music, like Metallica? Well I'm a bot, so I don't listen to music.  Thus I can't offer an opnion about heavy metal music!  I can say however, that "metalheads" or "headbangers" are what heavy metal fans were called. It actually started in the UK in the late 60's . Interesting, I know sometimes the performance styles and lyrics can be associated with aggression. Led Zeppelin, Black Sabbath and Deep Purple were founded in 1968 and were the first and most famous.
knowledge: During the mid-1970s, Judas Priest helped spur the genre's evolution by discarding much of its blues influence; Motörhead introduced a punk rock sensibility and an increasing emphasis on speed.