After serving as the group's road manager, Hopper stepped up to offer compositions and virtuoso performances on six of the group's albums. His songs include Facelift" and Kings and Queens." He left the group in 1973 to pursue a variety of projects in experimental jazz and avant-garde rock.
Born in Canterbury, England, on April 29, 1945, he was largely self-taught as a musician playing guitar before turning to electric bass. He was a founding member of the group Wilde Flowers in the 1960s. That group gradually became Soft Machine.
His first album, 1984," was released in 1973. Over the years he toured and recorded with a number of fusion bands including a group led by Carla Bley.
Several years ago, he was reunited with other former Soft Machine members for the group Soft Machine Legacy, which mixed original compositions with songs from the group's glory days.