February 13th, 1970, a celebration of Black Sabbath's 40th anniversary

This weekend marks the 40th anniversary of Black Sabbath’s eponymous debut album, released on February 13th, 1970…a Friday, of course. Their first album featured a new, moody and darkly atmospheric brand of rock music, and has long been considered the first true heavy metal album. Vocalist Ozzy Osbourne's ominous lyrical content, combined with Tony Iommi's down-tuned doomy guitar work set the standard for what heavy metal eventually evolved into. Interestingly enough, their place in history owes as much to a confluence of unique events as it does to their talent.

In 1968, the break up of two bands, led to the formation of one group which would transform into Black Sabbath. Iommi and drummer Bill Ward parted ways with Mythology while Osbourne and bassist Geezer Butler were part of the disbanded act, Rare Breed. The four came together to create a heavy blues band. The band name, The Polka Tulk Blues Band, could not have been farther in vision from Black Sabbath in sound or style. Polka Tulk as it was later shortened, included a second guitarist and a sax player.

Iommi would leave the band briefly in January 1969 to join another legendary rock act, Jethro Tull. Iommi's stay with the band was shortlived and upon his return, Polka Tulk, now called Earth, continued on, as a four-piece. The band soon discovered another act named Earth and once again looked to change their name. Across the street from their rehearsal studio a local theater was playing the 1963 Boris Karloff film, Black Sabbath. The band took notice of the line outside the theater and wondered at man's unique desire to be frightened. Ozzy later penned the lyrics for the band's classic track, "Black Sabbath," in part based on occult writer Dennis Wheatley works. The band began to create more songs in this gloomier style.

Tony Iommi (in white) performing on Rolling Stone's Rock and Roll Circus with Jethro Tull

Another aspect which filtered into the band's dark sound was due a a factory accident guitarist Iommi incurred on his right hand. He lost the tips of two of his fingers, and being left handed, almost gave up playing completely as he frets with his right hand. However some cleverly devised leather covered finger thimbles and the use of lighter gauge strings kept Iommi's dream alive. After Sabbath's first two studio albums, Iommi began detuning his guitar from E to C# (3 half-steps down), in order to ease the tension on his damaged fingers. This added an even brodier element to the band's now trademark sound. Sabbath were among the first bands to detune, which is now a common practice in heavy metal. Judas Priest vocalist Rob Halford has publicly referred to Iommi as: "The man who invented the heavy metal riff."

Sabbath's landmark, self-titled debut album was produced by Rodger Bain and recorded over two days at Regent Sound Studios, in London. The band spent one day recording and one mixing. The album was released by Vertigo Records in Europe on a fittingly cold and ominous Friday the 13th in 1970. The U.S. release would not come until May of that year on Warner Bros. Records, and the track "Evil Woman" would be replaced by "Wicked World."

Critics largely panned the album, including Rolling Stone critic Lester Bangs who would call it "just like Cream! But worse". Further dismissing the band as, "a shuck—despite the murky song titles and some inane lyrics that sound like Vanilla Fudge paying doggerel tribute to Aleister Crowley, the album has nothing to do with spiritualism, the occult, or anything much except stiff recitations of Cream clichés".

Ironically, in 2003, Black Sabbath was ranked 241st on Rolling Stone's list of the 500 greatest albums of all time.

New York's Village Voice called it "the worst of the counterculture on a plastic platter."

In 2000, Q Magazine hailed Black Sabbath as one of the "Best Metal Albums of All Time," claiming the album "was to prove so influential it remains a template for metal bands three decades on. The band's signature song remains the scariest of all heavy metal songs."