The 1970s turned the heavier experiments of the late 1960s into fully developed genres. Hard rock emphasized riffs, volume and arena-scale performance, while heavy metal pushed toward darker atmosphere, sharper distortion and more extreme musical identities.
The foundational bands
Led Zeppelin, Black Sabbath and Deep Purple became the central early pillars, each emphasizing a different balance of blues, heaviness, speed and virtuosity.
Metal becomes more distinct
Judas Priest helped separate metal from blues rock through twin guitars, high vocals and a sharper visual identity, while AC/DC, Thin Lizzy and others broadened hard rock in parallel directions.
Why it matters
The decade established the sonic and visual vocabulary that later heavy metal, glam metal, thrash and countless hard-rock subgenres would build upon.