eric clapton invented metal
it would be easier to find a hay in a needle stack then answer your question
well everyone will have a different opinion on the first two. personally i think Black Sabbath started the whole metal scene. there are MANY different types of metal, doom metal, death metal, glam metal, alternative metal, nu metal, goth metal, power, progressive, speed, thrash, dark, extreme, industrial, black metal.... the list goes on and on. youll have to become a metalhead to recognize the wide varieties, but if you want examples of certain bands from each genre, i suggest Wikipedia.
first rock songs would be something like elvis or little richard buddy holly something along those lines there really isnt a first of anything b/c it was more of a eveloution into what it had become metal well heavy, dark, black, hard rock could be a metal like the big hair bands heavy would be like pantere tool twisted sister drowning pool dark and black would be like deicide and the difference between the two has to do with the drums and the style in which they sing or lack there of also what its they sing about
