Persistently struggling to maintain their record deal with Deram, Egg amicably disbanded in 1972. By this time Campbell had become interested in mysticism and was involved in the international spiritual movement Subud. Having unsuccessfully pursued work as a plumber and as a graphic designer, he was invited to compose music for a film by director David Anderson: this in turn led to him attending the Royal College of Music, studying the French horn and composition and gaining his ARCM diploma in 1974. With mixed feelings about his academic studies, he reunited with his former Egg bandmates for their final album "The Civil Surface" (also in 1974), which consisted of unreleased material written in 1971–72, including what many view as Campbell's masterpiece in the progressive rock canon, "Enneagram". The album was bolstered by two Campbell-composed wind quartets (which featured neither Stewart nor Brooks).