Mike delved deeper into rock music, forming another short-lived group called Barefoot with his brother Terry. This led him to work as a bassist for Kevin Ayers & The Whole World. Kevin Ayers had been a founding member of Soft Machine, but left the group in 1968. The following year they released the album Joy of a Toy, which led to a tour in 1970.

Among the members of The Whole World was David Bedford, playing keyboards. Bedford, a classically trained composer, became good friends with Mike, helping him compose an early version of what would become his first solo album. While touring with The Whole World, Mike came into contact with Centipede, a huge jazz orchestra led by Keith Tippett. The wide range of instruments they had at their disposal influenced Mike in the multi-instrumental character he would later bring to his own compositions.

Kevin Ayers & The Whole World recorded two albums, Shooting At The Moon and Whatevershebringswesing, before disbanding in August 1971. By then, Mike had transitioned from bassist to lead guitarist, and his masterful solos had already earned him a considerable reputation.

Between 1971 and 1973, Mike began to organize the musical ideas swirling in his head. Using a four-track recorder borrowed from Ayers—two tracks in one direction and two in the other—he discovered that covering the erase head with a small piece of cardboard allowed him to record on four tracks. This enabled him to begin recording the ideas necessary for his grand project: creating a symphony, similar to the large-scale orchestral compositions with different movements found in many classical works, but using instruments of all kinds, especially those from the world of pop-rock. It has been mentioned that Jean Sibelius's Fifth Symphony profoundly influenced him at that time.

With the tape recorder borrowed from Ayers, he went into the bedroom of the house he shared with the other members of the group, and the ideas for his new work slowly began to take shape. Once immersed in the project, Mike decided to play all the instruments himself, figuring that with his natural musical talent, he could master almost any instrument, from the xylophone to the grand piano, the classical guitar, the Farfisa organ, and so on. While still working with Kevin Ayers, he also helped with the recordings at the famous Abbey Road Studios in London, where he had the opportunity to chat with The Beatles. He soon discovered that the studio had a storeroom full of all kinds of instruments, some of which belonged to the Liverpool quartet, so he would manage to arrive early and, while the other studio users arrived, he would experiment with those instruments and incorporate new sounds and textures into his project. Engrossed in a project he knew would be revolutionary, he set out to capture all the profound emotions he was experiencing as an explorer of uncharted musical territory. The work he was composing would also become a vehicle for releasing his deepest emotions, those he was finding most difficult to live with.

After creating a first demo, he began approaching record labels, trying to convince someone to support his project. But all the responses he received were negative. They all insisted on the lack of commercial appeal of Oldfield's work and that, even if it were ever released, no one would distribute it.