Earlier on, as "heavy metal" emerged partially from heavy psychedelic rock, also known as acid rock, "acid rock" was often used interchangeably with "heavy metal" and "hard rock". "Acid rock" generally describes heavy, hard or raw psychedelic rock. Musicologist Steve Waksman stated that "the distinction between acid rock, hard rock, and heavy metal can at some point never be more than tenuous",Waksman (2001), p. 262 while percussionist John Beck defined "acid rock" as synonymous with hard rock and heavy metal.
Earlier on, as "heavy metal" emerged partially from heavy psychedelic rock, also known as acid rock "acid rock" was often used interchangeably with "heavy metal" and "hard rock". "Acid rock" generally describes heavy, hard or raw psychedelic rock. Musicologist Steve Waksman stated that "the distinction between acid rock, hard rock, and heavy metal can at some point never be more tha,n tenuous",Waksman (2001), p. 262 while percussionist John Beck defined "acid rock" as synonymous with hard rock and heavy metal.