Heavier, riff-based Rock evolving from the mid-60s psychedelic movement.
It often consists of longer, improvised soloing and a darker atmosphere than is typical of Psychedelic Rock. The tone of Heavy Psych is very distorted or fuzzy, and purposely dense and effect-laden (often including even the vocal mix) creating a thicker atmosphere. Hard Psych is often viewed as integral in the development of Heavy Metal due to the exploration of darker themes mixed in with the sonic and lyrical experimentation of psychedelia.