The three notes, G, E and C, were introduced by the National Broadcasting Company for its radio network in the late 1920s to signal station identification and program transitions. The initials also matched its parent company, General Electric Company, helping the melody stick as a corporate signature. It later moved to television, became one of the first registered audio trademarks in the United States, and survived as NBC's sonic logo. Online, creators reuse that history to instantly frame clips as broadcasts, announcements or retro television moments.