In early 2013 a rigid 30 second video format swept the world. One helmeted person dances alone to Baauer’s trap track Harlem Shake while everyone nearby ignores them. At 15 seconds the bass drops, the shot cuts, and the whole room erupts in costumes and flailing. YouTube creator George Miller, later known as Joji, sparked it on January 30, and five Australian teenagers fixed the template days later. It had nothing to do with the original 1980s Harlem street dance.

This episode treats the meme as more than a joke. With one locked camera and one jump cut, anyone could take part, and by February 10 new versions were appearing at 4,000 a day. Sports teams, armies, The Simpsons, and 60 ad agencies joined in. Schools, employers, and governments answered with suspensions, firings, and arrests, protesters adopted the format in Egypt and Tunisia, and the music industry had to change how it counts a hit.

• The meme passed one billion cumulative views in 40 days, half the time Gangnam Style had needed.
• Fifteen Australian miners were fired for filming underground, an Oxford librarian lost her job, and two Israeli soldiers were sentenced to prison.
• Billboard began counting YouTube streams in the Hot 100, and Baauer’s track debuted at number one. Without that data it would have only reached the top 15.
• Label Mad Decent left fan videos up and used YouTube’s Content ID to collect ad revenue from them instead of issuing takedowns.
• In December 2017 Baauer and his label finally took legal action when FCC chairman Ajit Pai danced to the song in a video promoting net neutrality repeal.