A rock subgenre which has its earliest roots in early-1960s garage and psychedelic rock. It is typified by a heavy use of distorted electric guitars, bass guitar and drums. The term is often used as an umbrella term for genres such as punk and grunge in order to distinguish them from the more radio-friendly pop rock genre.

Hard rock is strongly influenced by blues music, but unlike traditional rock (which takes elements of more traditional blues), hard rock incorporates elements of 'British blues', a style of blues played with more modern instruments such as electric guitars, drums, keyboards and electric bass.

During the 1970s, hard rock inspired a new genre of music known as heavy metal (or just metal). The distinction between the two genres can be subtle and often comes down to a band's image, rather than its songs. The two genres also have some crossovers - for example; heavy metal pioneers such as Black Sabbath, Led Zeppelin and Deep Purple are often considered both heavy metal and hard rock, whereas bands such as AC/DC, Aerosmith, Thin Lizzy, Guns N' Roses, Nazareth, Van Halen and KISS are normally referred to as hard rock.

Hard rock emerged from British groups of the late-1960s such as Black Sabbath and Led Zeppelin, who mixed the music of early British rock bands with a more hard-edged form of blues rock. Led Zeppelin's first album, Led Zeppelin I (1969), is an example of blues rock which represents the beginning of the hard rock genre.