First Call originated as a United States military bugle call, a short brass signal used to alert soldiers that a formation, ceremony, or duty was about to begin. Army bands have long performed it at official occasions, and the same clear melody later became familiar at sporting events, particularly horse racing, where it helps build excitement before the start. Online, creators have adopted it as a quick audio shorthand for something beginning, from competitions and challenges to staged entrances, because listeners instantly recognise its formal, get-ready tone.