Harlem shake

"The Harlem Shake is an Internet meme that went viral on YouTube in February 2013. The meme is in the form of a video that began being replicated according to a similar concept by many people.

The art form of the meme was established in a video uploaded on February 2 by The Sunny Coast Skate, five teenagers from Queensland, Australia.

The videos last 30-something seconds and feature an excerpt from the song "Harlem Shake" by electronic musician Baauer. Usually, a video begins with one person (often helmeted or masked) dancing to the song alone for 15 seconds, surrounded by other people not paying attention or unaware of the dancing individual. When the bass drops, the video switches to the entire crowd doing a crazy convulsive dance for the next 15 seconds."

source Wikipedia