Black Sabbath - Vol 4
There were two albums I discovered at the same time, on the same day, on a cassette that my best friend stole from his older sister - she listened to a lot of hard rock and rock music, and he would frequently steal her music cassettes and loan them to me. On one side was Black Sabbath Vol 4 from 1972 and on the other side of the cassette was Pink Floyd's Wish You Were Here from 1975, and both of those albums completely overwhelmed my existing horizons and opened up new worlds for me. I got this cassette in 1975 and when I listened to Vol 4 I had never heard music of such heaviness and darkness before. Literally every song on this album is fantastic. The album has a very murky, very imperfect production but that added to the mystery of this band; it made the songs even more dark and even more evil. It was like a drug - I couldn't stop listening to this album. I had to give back the cassette, but I went back to the store and got myself the album in vinyl. It's probably the most important hard rock album in my entire life: it shaped my understanding of hard music, and a few years later I started learning guitar from this album. I would sit down in front of the record player and explore my guitar playing by trying to figure out the riffs that Tony Iommi is playing on Vol 4.