The dun dun sting comes from the Law & Order franchise created by Dick Wolf, with the original series premiering in 1990 and Special Victims Unit following in 1999. Composer Mike Post designed the metallic two-note sound to punctuate scene changes between police investigation and courtroom drama. As reruns and clips flooded YouTube and later TikTok, creators detached it from the show and turned it into shorthand for any dramatic reveal. It endures because two notes instantly tell viewers something serious or incriminating just happened.