"The Wizard" is the second track of Black Sabbath's 1970 debut album Black Sabbath.
Sources claim it is about the band's drug dealer at the time (and may be partly true), but bassist Geezer Butler claims the character Gandalf from The Lord of the Rings as his inspiration.
"The Wizard" was a favorite of the band, and was later included on compilation albums We Sold Our Soul for Rock 'n' Roll and Symptom of the Universe. Zakk Wylde, the guitarist for Ozzy's solo band made a cover of it on the Japanese import and reissue prints of his Pride & Glory album, and Cypress Hill sampled some harmonica notes in "We Ain't Going Out Like That". Enigma sampled the harmonica notes on track 4, "I Love You ... I'll Kill You" on the album The Cross of Changes. In 1994 it also formed part of the popular album, Nativity in Black, which was a tribute to Black Sabbath. This slightly altered version was performed by the Bullring Brummies, which was made up of Geezer Butler & Bill Ward of Black Sabbath, Rob Halford of Judas Priest, Brian Tilse of Fight and Scott Weinrich of The Obsessed.
This song was covered by New Zealand band Shihad on their Devolve EP.
It also served as the inspiration for the song "Cities on Flame with Rock and Roll", by Blue Öyster Cult.
Despite its apparent popularity, the song was never played live until the tour of 1994, supporting the album Cross Purposes, with the harmonica part played by vocalist Tony Martin. It had been played subsequently during several shows after the reunion of the original lineup. - wiki