In his teenage years, Isaacs became a veteran of the talent contests that regularly took place in Jamaica. In 1968, he made his recording debut as Winston Sinclair, with the single "Another Heartache", recorded for Producer Byron Lee. The single sold poorly and Isaacs went on to team up with two other vocalists (Penroe and Bramwell) in the short-lived trio The Concords, recording for Rupie Edwards and Prince Buster. The trio split up in 1970 and Isaacs launched his solo career, initially self-producing recordings and also recording further for Edwards. In 1973, he teamed up with another young singer, Errol Dunkley to start the African Museum record label and shop, and soon had a massive hit with "My Only Lover", credited as the first lovers rock record ever made. He recorded for other producers to Finance further African Museum recordings, having a string of hits in the three years that followed, ranging from ballads to roots reggae, including "All I Have Is Love", "Lonely Soldier", "Black a Kill Black", "Extra Classic" and his cover version of Dobby Dobson's "Loving Pauper". In 1974, he began working with Producer Alvin Ranglin, and that year he had his first Jamaican no. 1 single with "Love Is Overdue".