What is this "Harlem Shake" craze

Gangnam Style is so last year: 2013's new dance craze is the Harlem Shake.

But that's also the name of an old-school dance craze. Back in the '80s, the body-quaking move was invented at a Harlem basketball game. From there, it went on to become a hip-hop dance move involving shimmies (shoulder shakes), tics (robotic starts and stops) and pops (leg spasms).

Now, the Harlem Shake is best known as the video meme with the dance song Harlem Shake by Baauer. And it's still quite spastic. Check out this playlist of popular Harlem Shake videos.
The formula for the Harlem Shake video is as follows:

• One person — often a helmeted man gently hip-thrusting — enjoys the sweet beats of Harlem Shake by Baauer in a roomful of oblivious people.
• Then, the bass drops. Jump cut.
• Everyone is Harlem Shaking, flailing, jumping and punching an inflatable giraffe.

The videos are short (about 30 seconds), easy to make (anyone can flail) and are filmed everywhere: underwater, in concert, at an Army base and on Today.

According to Kevin Allocca, YouTube trends manager, Harlem Shake video uploads have skyrocketed in the last few days. He writes that as of Feb. 11, 12,000 Harlem Shake videos have been posted this month. Those videos — more than 4,000 of which are posted each day — have been watched upward of 44 million times.

Harry "Baauer," of Diplo's Mad Decent label, has seen his dance track Harlem Shake climb the charts since it was released five months ago. It now sits at No. 10 on the iTunes Songs chart.

Tweeted Baauer, "this harlem shake stuff is blowing my mind."