Gamelan is a State Military Officer with the Third Sovereign Battalion in Central City. When his team is called out to provide backup to Führer King Bradley in Episode 56, he moves out in an attempt to retake the Central Command headquarters' main gate from the soldiers of Fort Briggs. Unfortunately for Gamelan, he and all the members of his platoon are swiftly rendered unconscious from an attack by the newly arrived Fu. In the manga, his role is instead played by the recurring character Storch, making Gamelan an anime-only substitution.
It is possible Gamelan's name is based off that of Maurice Gamelin, the French commander-in-chief during the early years of the Second World War.