heavier 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 60s with the garage, psychedelic and blues rock movements. the genre developed into a major form of popular music in the 70s. during the 80s, some hard rock bands moved away from their hard rock roots and more towards pop rock.

• reference artists:

guns n roses, deep purple, led zeppelin, ac/dc, aerosmith, kiss.

• important hard rock album:

guns n' roses - appetite for destruction (1987)