Black Sabbath-Vol. 4 (1972)

With their fourth album, Black Sabbath confirmed their tendency to experiment with heavy metal sounds. For this new album, titled "Vol. 4", Tony Iommi took the reins of production alongside Patrick Meehan, and this is reflected in the tuning of his guitar, which he altered even further than on the previous album, "Master of Reality", giving his sound a heavier and darker tone. Recorded in Los Angeles, their first album recorded outside the UK, it was marked, among other things, by the break the band had taken after a period of instability due to drug abuse by all its members and the exhausting tours around the world promoting the previous album. Despite not abandoning their roots, this new release no longer features such satanic or dark imagery in its lyrics, making it musically a less consistent work compared to their earlier albums. However, there are some memorable moments, such as the progressive heavy rock epic "Wheels of Confusion", in which Tony Iommi showcases his immense talent with impressive guitar riffs and solos. The distinctive Black Sabbath sound is still present in the heavy metal tracks "Supernaut", "Snowblind", and "Cornucopia", and in the frenetic heavy rock anthem "Under the Sun". The rest of the album consists of more predictable tracks like the stoner rock anthems "Tomorrow's Dream" and "St. Vitus Dance", and the melancholic ballad "Changes". Although for many fans this album was somewhat of a step backward in the band's career, it achieved multi-platinum status in the North American market and a gold record in the UK.