Dunbar's earliest inspiration for playing the drums was sparked while watching Lloyd Knibbs and the Skatalites on television. During a 1997 interview, he recalled, "I saw (Knibbs) playing and I thought, 'I want to be a drummer' because he's the hardest worker in the band. He's my idol! In some ways, I'm self-taught but I got a lot of help from other drummers by watching them play."
Dunbar, whose nickname was reportedly given to him for his passion for Sly & the Family Stone, launched his musical career while still in his teens, playing with a local group, the Yardbrooms at the age of 15. His recording debut came, in 1969, when he appeared on an album, Double Barrel, by Dave and Ansell Collins. He subsequently continued to play with Ansell Collins in a band, Skin, Flesh and Bones.
Meeting Robbie Shakespeare, then playing bass for the Hippy Boys, in 1972, Dunbar began a life-long friendship.When Shakespeare was asked to recommend a drummer for a recording session for producer Bunny Lee's Aggrevators, he remembered Dunbar. Following the session, Dunbar and Shakespeare agreed to keep working together.Their first break came when they accompanied Peter Tosh on his album, Legalize It!, in 1976. The duo continued to play with Tosh's band until 1979, recording four additional albums — Equal Rights, Bush Doctor, Mystic Man, and Wanted: Dread And Alive, and producing Tosh's hit duet with Mick Jagger, "(Keep On Walking) Don't Look Back)," in 1978. According to legend, the duo lived on bread and water while touring with Tosh, to save enough money to start their own production company. Their persis tance paid off. Shortly after leaving Tosh's group, Dunbar and Shakespeare launched Taxi Productions and formed a studio band, The Taxi All-Stars.Their first session yielded a number one Jamaican hit, "Soon Forward," for Gregory Isaacs.