Oldfield's career began fairly early, playing acoustic guitar in local folk clubs. At this time, he already had two fifteen-minute instrumental pieces in which he would "go through all sorts of moods", a precursor to his landmark 1970s compositions. In his early teens, Oldfield was involved in a 'beat group' playing Shadows-style music (he has often cited Hank Marvin as a major influence, and would later cover The Shadows' song "Wonderful Land") In 1967 he and his sister Sally formed the folk duo The Sallyangie and were signed to Transatlantic Records after exposure in the local folk scene. An album, Children of the Sun, was issued in 1968. After Sallyangie disbanded, he formed another duo with his brother Terry, called Barefoot, which took him back to rock music.
In 1970 he joined The Whole World - backing group to vocalist Kevin Ayers, formerly of the Soft Machine - playing bass guitar and occasionally lead guitar. The band also included keyboardist and composer David B.