Few bands were as critically reviled in their day as Black Sabbath. And still fewer have seen their reputation rehabilitated as much in the years since their peak. Black Sabbath had once earned the nearly universal scorn of the rock critic establishment for their oppressively heavy, simplistic riffs, the bad rhymes of their lyrics, their melodrama, their lumbering, plodding tempos, their sludgy sound and their Christian/Satanic/Druggy/Magical iconography. In other words, they were despised for essentially the very things their fans loved them for.

What is undeniable now is that the band is almost universally acknowledged as being the archetypical heavy metal band, and subsequently one of the most influential bands in history. It is almost impossible to count the bands formed in their wake that mine the same essential approach; in this sense they rank up there with bands like the Rolling Stones, the Byrds, and the Velvet Underground in influence. Furthermore, the sheer mammoth din of their albums has gained resonance over the years, making them seem somehow better than they once did, now that heavy metal has become a familiar concept to all.

Sonically, the band was an organic thing. Its roots lay in the heaviest of late-60's acid rock; in Black Sabbath, one can hear traces of Cream, Blue Cheer, and Vanilla Fudge. These bands were the missing links between psychedelia and heavy metal; they took psychedelic blues-rock and amped it up to deafening proportions; giving themselves gigantic sounds. Black Sabbath took this approach a step further, slowing down the tempos, stripping away the psychedelia, increasing the volume even more, playing up their mystical and frightening lyrics, and shining a spotlight on Ozzy Osbourne's bluesy wail. The result was a sound bigger than anyone could imagine; it represented the very extreme edge of rock. This was potent stuff, and even if the critics ridiculed it, the band sold a huge amount of records and built an enduring legacy that only grows richer with time.

The members had known each other as teenagers in their hometown of Aston, not far from Birmingham, England. Tony Iommi and Bill Ward had played together in a band called Mythology, while John "Ozzy" Osbourne and Terence "Geezer" Butler had worked together in a band called Rare Breed. The four of them came together in a new outfit called the Polka Tulk Blues Band, which formed in August of 1968. Also known simply as "Polka Tulk" the band landed a few professional gigs in the Birmingham area, playing a jazzy-blues somewhat reminiscent of the Graham Bond Organization, once fronted by Jack Bruce. After a few months, the band changed its name to Earth, and began getting better gigs.

Earth was known for its high volume live shows, which generated positive response from the audience, so the band amped it up even further. Due to an accident, Iommi had lost a fingertip; as a result he purposely kept the strings on his guitar slack, tuning them down an octave; this low-register tuning coupled with massive amplification created that classic heavy Sabbath sound. Meanwhile, Butler had developed an interest in the occult, and had become fascinated with the black magic novels of Dennis Weatley. Inspired, he wrote the song "Black Sabbath", full of dark black magic imagry. The song was a crowd pleaser, and Osbourne and Butler decided to do more in a similar vein, reasoning that a musical version of a horror show might become a big thing. After some confusion at a gig due to another band using the name "Earth", they renamed themselves Black Sabbath.