The theme was written by Lalo Schifrin for the original Mission: Impossible television series, which first aired in 1966, and its unusual 5/4 rhythm quickly made it synonymous with espionage. The motif was revived for the film series beginning in 1996 and has since become a shorthand for covert operations in popular culture. Creators reuse the short riff because listeners recognise it instantly, even without seeing the source, and it instantly signals a plan, a heist or a daring escape.