Heavy Prog defines progressive rock music that draws as much influence from hard rock as it does from classic prog rock. In simple terms, it is a marriage of the guitar-based heavy blues of the late 1960's and 1970's -artists such as Cream, Led Zeppelin, and Black Sabbath- and the progressive/symphonic movement represented by King Crimson, Yes and Genesis. The electric guitar, amplified to produce distortion or overdrive is a crucial element, providing the heavy tone required for this aggressive style, and later for the British and North American heavy metal of the late 1970's and 80's. The primary rock format of drums, bass and guitar with keys and/or vocals on top is represented strongly in heavy prog. The presence of the Hammond organ with its deep, intense rumble was also common among harder progressive groups such as Atomic Rooster. Although certain other acts, such as King Crimson and Jethro Tull, utilize a heavy guitar, bass and keyboard sound, the bulk of their work over the years puts them in a different category. Bands that represent Heavy Prog would include Rush, Atomic Rooster, Porcupine Tree, The Mars Volta, Uriah Heep, Tempest, Black Widow.
Atomic Rooster-Death Walks Behind You (Death Walks Behind You, 1970 UK)