Hopper grew up in Canterbury area of England starting his music journey on guitar and alto saxophone. He joined Wilde Flowers with his friend and Robert Wyatt. the Wilde Flowers eventually evolved into both Soft Machine and Caravan. Soft Machine went on to support Jimi Hendrix during one of his first tours. This tour is where the magic happened: the previous bassist for Soft Machine left and Hopper was asked to replace him. With Hopper’s talent on bass, Soft Machine transformed into a high-powered band with inspired music.
Hopper’s work with Soft Machine continued for multiple albums and he produced many solo compositions in his career. Hopper is credited as a driving force in the initial prog-rock/jazz fusion movement influencing Pink Floyd, King Crimson and many more.