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AllMusic
Christgau's Record Guide	C−
Encyclopedia of Popular Music
MusicHound Rock	4/5
The Rolling Stone Album Guide
Sputnikmusic	4/5

Black Sabbath is the debut studio album by the English rock band Black Sabbath. Released on 13 February 1970 in the United Kingdom and on 1 June 1970 in the United States, the album reached number eight on the UK Albums Charts and number 23 on the Billboard charts. Although it was poorly received by most contemporary music critics at the time, Black Sabbath has since been credited as one of the most influential albums in the development of heavy metal music.

According to Black Sabbath guitarist and founder member Tony Iommi, the group's debut album was recorded in a single day on 16 October 1969. The session lasted twelve hours. Iommi said: "We just went in the studio and did it in a day, we played our live set and that was it. We actually thought a whole day was quite a long time, then off we went the next day to play for £20 in Switzerland." Aside from the bells, thunder and rain sound effects added to the beginning of the opening track, and the double-tracked guitar solos on "N.I.B." and "Sleeping Village", there were virtually no overdubs added to the album. Iommi recalls recording live: "We thought, 'We have two days to do it and one of the days is mixing.' So we played live. Ozzy (Osbourne) was singing at the same time, we just put him in a separate booth and off we went. We never had a second run of most of the stuff."

Key to the band's new sound on the album is Iommi's distinctive playing style that he developed after an accident at a sheet metal factory where he was working at the age of 17 in which the tips of the middle fingers of his fretting hand were severed. Iommi created a pair of false fingertips using plastic from a dish detergent bottle and detuned the strings on his guitar to make it easier for him to bend the strings, creating a massive, heavy sound. "I'd play a load of chords and I'd have to play fifths because I couldn't play fourths because of my fingers," Iommi explained to Phil Alexander in Mojo in 2013. "That helped me develop my style of playing, bending the strings and hitting the open string at the same time just to make the sound wilder." In the same article bassist Geezer Butler added, "Back then the bass player was supposed to do all these melodic runs, but I didn't know how to do that because I'd been a guitarist, so all I did was follow Tony's riff. That made the sound heavier."

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