By Raelyn Johnson and Alicia W. Stewart, CNN
(CNN) - It begins rather innocently.
An infectious track, a conservative, solo dancer and a few oblivious observers.
A mere fifteen seconds of pelvic thrusts, then, a roar of a lion, a drop of a beat...
Then, everyone goes CRAZY.
The “Harlem Shake” is the No. 1 song on the Billboard Hot 100 for the second week in a row, a top 10 iTunes download and the meme of the moment. Millions are watching variations on the “Harlem Shake” video theme in which the dance starts with one person thrusting their pelvis or dancing solo for 15 seconds, while the people in the background ignore them. Then when the beat drops, a group joins in bizarre, repetitive movements. The whole dance lasts around 30 seconds.
While this latest trend is built around the “Harlem Shake", it has scant ties with the New York neighborhood, and very little in common with the original dance that shares its name.
So just how did the phenomenon begin? It starts with a dancer in Harlem, a producer from Philadelphia and ends with you.