Inspired by John Lennon, Butler played rhythm guitar in his pre-Sabbath days, including with Rare Breed. When Sabbath was formed, Iommi made it clear that he did not want to play with another guitarist, so Butler moved to bass. According to Butler, "I'd never played bass until I was on stage at the first gig that we played. Borrowed the bass guitar off one of my friends and it only had three strings on it." Butler lists Jack Bruce of Cream as his biggest influence as a bassist. Iommi described Butler as being "from another planet" in the band's early days; he took LSD, wore Indian hippie dresses, and was very peaceful. At the time Black Sabbath was formed, Butler was studying to become an accountant, and this training resulted in him managing the band's finances in the early days.