hard rocking

Hard Rock established itself in the 1970's when bands like Led Zeppelin for example got away from the more acid rock bands like Jimi Hendrix, Cream, Iron Butterfly who were more psychedelic and less blues. It was Led Zeppelin who set the prototypical hard rock sound that would be imitated from the 1970's to the present. Hard Rock is also much more commerical friendly than Heavy Metal.