Hard rock or heavy rock is a loosely defined subgenre of rock music typified by a heavy use of aggressive vocals, distorted electric guitars, bass guitar, and drums, sometimes accompanied with keyboards. It began in the mid-1960s with the garage, psychedelic and blues rock movements. Some of the earliest hard rock music was produced by the Kinks, the Who, the Rolling Stones, the Yardbirds, Cream and the Jimi Hendrix Experience. In the late 1960s, bands such as the Jeff Beck Group, Iron Butterfly, the Beatles, Led Zeppelin, Golden Earring, Steppenwolf and Deep Purple also produced hard rock.
