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. The dancing style should not be confused with the original Harlem Shake dance.[6] Also, in the second half of the video, people often wear a minimum of clothes or crazy outfits or costumes while wielding strange props.[7][8]

Now the trend is to take old viral video and movie clips and add the song to the scene!

The first remix I discovered

Which led me to this one

This one is my favorite!