Acid rock

Acid rock is a style or subgenre of psychedelic rock which emerged during the 1960s psychedelic era among rock bands, many of whom aspired for sociological and cultural change and used, or anticipated listeners using, lysergic acid diethylamide (LSD or "acid"). The term has several characterizations and may often refer to a louder, heavier, and intense variety of psychedelic rock, representing both "good trips" and "bad trips." It is generally defined by distorted guitars, lyrics that contain drug references, and long improvised jams. It may also include a subset of bands that were part of, or were influenced by, the San Francisco Sound.