After the psychedelic sounds taht came out of the 60', the 70's would offer a brand new sound. A much heavier sound, the one that would start off years of hard rock.
This early brand of hard rock is nothing like the sounds taht we ear now and in many cases people don't even consider them as "heavy." The one thing that they did ahve in common with todays hard rock bands is taht they were pissed and had better things to writte about then love songs.
The style called "Heavy Metal" was started. The name came from the lyric, Heavy metal thunder, from the 1967 hit song, Born to be wild, written by the band Steppenwolf.
The 70's would spawn bands that would influence the following generations of hard rock bands, including big names such as, Led Zeppelin, Deep Purple, Black Sabbath, Aerosmith, Blue Oyester Cult, Judas Priest and Queen, just to name a few.