Master of Reality is the third album by the British heavy metal band Black Sabbath, released in 1971. It is sometimes noted as the first stoner rock album. Master of Reality was certified double platinum after having sold over 2 million copies. The slow and heavy songs that compose most of the album are interspersed with quiet ballads written by Tony Iommi. Two of these, "Embryo" and "Orchid", are short instrumentals serving as interludes. The third, "Solitude", is much longer in comparison and features Ozzy Osbourne's soft, woeful vocals. Unusually, the lyrics of the song "After Forever" written by Terry "Geezer" Butler , focus entirely on Christian themes. At the time, some viewed Black Sabbath as Satanists due to their dark sound, image and lyrics. Similarly, the song "Lord of this World" has lyrics that deal with Satan mocking those who unwittingly follow him. It was released as a single along with "Fairies Wear Boots" in 1971." The song "Solitude" showcases Tony Iommi's multi-instrumental talents, featuring him playing the guitar, flute and piano. The album opener, "Sweet Leaf", is a song about cannabis. "Children of the Grave" was written about war, peace and revolution.