Conversation so far:
What is Radio Gnome Invisible trilogy by Gong?
The band, Gong's Radio Gnome Invisible trilogy, describes the adventures of Zero the Hero, the Good Witch Yoni and the Pot Head Pixies from the Planet Gong.

Question: What was Tubular Bells?
Self-contained rewrite: What was Tubular Bells in relation to Radio Gnome Invisible trilogy by Gong?