Master of Reality and Volume 4 (1971–1973)

In February 1971, Black Sabbath returned to the studio to begin work on their third album. Following the chart success of Paranoid, the band were afforded more studio time, along with a "briefcase full of cash" to buy drugs.[26] "We were getting into coke, bigtime", Ward explained. "Uppers, downers, Quaaludes, whatever you like. It got to the stage where you come up with ideas and forget them, because you were just so out of it."[27]
Production completed in April 1971, and in July the band released Master of Reality, just six months after the release of Paranoid. The album reached the top ten in both the US and UK, and was certified gold in less than two months,[28] eventually receiving platinum certification in the 1980s[28] and Double Platinum in the early 21st century.[28] Master of Reality contained Black Sabbath's first acoustic songs, alongside fan favourites such as "Children of the Grave" and "Sweet Leaf".[29] Critical response of the era was again unfavourable, with Lester Bangs of Rolling Stone dismissing Master of Reality as "naïve, simplistic, repetitive, absolute doggerel", although the very same magazine would later place the album at number 298 on their 500 Greatest Albums of All Time list, compiled in 2003.[30]
Following the Master of Reality world tour in 1972, Black Sabbath took its first break in three years. As Bill Ward explained: "The band started to become very fatigued and very tired. We'd been on the road non-stop, year in and year out, constantly touring and recording. I think Master of Reality was kind of like the end of an era, the first three albums, and we decided to take our time with the next album."[31]
In June 1972, the band reconvened in Los Angeles to begin work on their next album at the Record Plant. The recording process was plagued with problems, many as a result of substance abuse issues. While struggling to record the song "Cornucopia" after "sitting in the middle of the room, just doing drugs",[32] Bill Ward was nearly fired from the band. "I hated the song, there were some patterns that were just... horrible" Ward said. "I nailed it in the end, but the reaction I got was the cold shoulder from everybody. It was like 'Well, just go home, you're not being of any use right now.' I felt like I'd blown it, I was about to get fired".[33] The album was originally titled "Snowblind" after the song of the same name, which deals with cocaine abuse. The record company changed the title at the last minute to Black Sabbath Vol. 4, with Ward stating "There was no Volume 1, 2 or 3, so it's a pretty stupid title really".[34]
Black Sabbath's Volume 4 was released in September 1972, and while critics of the era were again dismissive of the album, it achieved gold status in less than a month,[35] and was the band's fourth consecutive release to sell a million copies in the US.[19][35] With more time in the studio, Volume 4 saw the band starting to experiment with new textures, such as strings, piano, orchestration and multi-part songs.[36] The song "Tomorrow's Dream" was released as a single—the band's first since Paranoid—but failed to chart.[37] Following an extensive tour of the US, the band travelled to Australia for the first time in 1973, and later mainland Europe.

Black Sabbath and Paranoid (1970–1971)

Black Sabbath were signed to Philips Records in December 1969, and released their first single, "Evil Woman" through Philips subsidiary Fontana Records in January 1970. Later releases were handled by Philips' newly formed progressive rock label, Vertigo Records. Although the single failed to chart, the band were afforded two days of studio time in late January to record their debut album with producer Rodger Bain. 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 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."[18]
The eponymous Black Sabbath was released on Friday the 13th, February 1970. The album reached number 8 in the UK Albums Chart, and following its US release in May 1970 by Warner Bros. Records, the album reached number 23 on the Billboard 200, where it remained for over a year.[19][20] While the album was a commercial success, it was widely panned by critics, with Lester Bangs of Rolling Stone dismissing the album as "discordant jams with bass and guitar reeling like velocitised speedfreaks all over each other's musical perimeters, yet never quite finding synch".[21] It has since been certified platinum in both US by the Recording Industry Association of America (RIAA) and in the UK by British Phonographic Industry (BPI).[22][23]
To capitalise on their chart success in the US, the band quickly returned to the studio in June 1970, just four months after Black Sabbath was released. The new album was initially set to be named War Pigs after the song "War Pigs", which was critical of the Vietnam War. However Warner changed the title of the album to Paranoid, fearing backlash by supporters of the Vietnam War. The album's lead-off single "Paranoid" was written in the studio at the last minute. As Bill Ward explains: "We didn't have enough songs for the album, and Tony just played the (Paranoid) guitar lick and that was it. It took twenty, twenty-five minutes from top to bottom."[24] The single was released ahead of the album in September 1970 and reached number four on the UK charts, remaining Black Sabbath's only top ten hit.[20]
Black Sabbath released their second full-length album, Paranoid in the UK in October 1970. Pushed by the success of the "Paranoid" single, the album hit number one in the UK. The US release was held until January 1971, as the Black Sabbath album was still on the charts at the time of Paranoid's UK release. The album broke into the top ten in the US in March 1971, and would go on to sell four million copies in the US,[25] with virtually no radio airplay.[20] The album was again panned by rock critics of the era, but modern-day reviewers such as AllMusic's Steve Huey cite Paranoid as "one of the greatest and most influential heavy metal albums of all time", which "defined the sound and style of heavy metal more than any other record in rock history".[2] Paranoid's chart success allowed the band to tour the US for the first time in December 1970, which spawned the release of the album's second single "Iron Man". Although the single failed to reach the top 40, "Iron Man" remains one of Black Sabbath's most popular songs, as well as the bands highest charting US single until 1998's "Psycho Man".[19]