More About Hard rock

Hard rock is a style of rock music built around distorted electric guitars, forceful vocals, prominent riffs and a blues-influenced rhythmic foundation, emerging in the late 1960s and becoming one of the defining sounds of modern rock.
Early hard rock was shaped by bands including Led Zeppelin, Deep Purple, the Who, Cream, Black Sabbath and AC/DC, whose music helped define the genre during the late 1960s and 1970s.
Hard rock generally retains stronger roots in blues rock and traditional rock and roll, often placing greater emphasis on melody and groove. Heavy metal typically features heavier riffs, darker themes, faster tempos and more aggressive vocals, although the two genres frequently overlap.