Master of Reality is the third studio album by English heavy metal band Black Sabbath, released on 21 July 1971 by Vertigo Records. It is regarded by some critics as the foundation of doom metal, stoner rock, and sludge metal. Produced by Rodger Bain, who also produced the band's prior two albums, Master of Reality was recorded at Island Studios in London from February to April 1971. Guitarist Tony Iommi and bassist Geezer Butler downtuned their instruments during the production, achieving what Iommi called a "bigger, heavier sound".

Master of Reality peaked at number five on the UK Albums Chart and number eight on the US Billboard 200.[citation needed] Negatively received by critics on release, the album is now considered one of the greatest heavy metal albums of all time. It was certified double platinum after having sold over two million copies.

Tracklist

• Sweet Leaf
• After Forever
• Embryo
• Children of the Grave
• Orchid
• Lord of This World
• Solitude
• Into the Void