Terry "Geezer" Butler, born on July 17, 1949, is an English musician best known as the bassist and primary lyricist for the pioneering heavy metal band Black Sabbath. He is recognized for his significant contribution to the development of the heavy metal genre, particularly through his innovative bass playing and dark, often philosophical lyrics. Butler co-founded Black Sabbath in 1968, alongside guitarist Tony Iommi, drummer Bill Ward, and vocalist Ozzy Osbourne. The band's self-titled debut album, released in 1970, is considered one of the first heavy metal albums. Notable works include the albums "Paranoid" (1970), "Master of Reality" (1971), and "Sabotage" (1975), which feature classic tracks like "Iron Man," "War Pigs," and "Fairies Wear Boots." Butler's lyrical themes often explore existentialism, war, and the occult, influencing countless artists and shaping the thematic direction of heavy metal. After multiple reunions and lineup changes, he remains a key figure in the genre, celebrated for his contributions to music and culture. His work has left an indelible mark, establishing Black Sabbath as one of the most influential bands in rock history.