On the aptly titled fourth album from the Heavy Metal Gods, they pretty much stick to the same doomy, sludgy, Down-esque sound that got them famous while experimenting with some new sounds. The album opens with the sonic blast of Wheels Of Confusion, which has been known to damage ears while played at a high volume (Only kiddin'). Then comes the heavy smasher Tomorrow's Dream, which is one of the band's signature songs. Then comes what is probably the worst song on the album: Changes. Don't get me wrong, it's OK, but it gets SO boring, just hearing the piano tinkle away while Ozzy keeps moaning. Calls for some high-velocity guitar. Then comes the bizzare 'song' FX, which is simply composed of little squeks and bangs. The first half closes with the spectacular Supernaut, an epic about space travel. The next song, Snowblind is probably the most famous song off this album. Great heaviness. Cornucopia, which comes next, is one of the album's best. It includes heavy music, great lyrics, and everything that makes a Sabbath song a Sabbath song. Laguna Sunrise is a Santana-sounding instrumental that shows Sabbath's lighter yet heavier sound. St Vitus' Dance is another hard-whacker, one of the album's heaviest. This song inspired the name of a later doom band, Saint Vitus. The album closes with the mighty and spectacular Under The Sun, which closes a classic album in full headbanger spirit. This is probably one of the most underrated albums from this band, because it is usually stands in the shadow of Master Of Reality and Paranoid, which are actually lesser albums. This is one of the most heavy albums of the 1970's. If ya don't own this album, you are not worthy of the title 'metalhead'.